Australia’s trusted independent immunisation experts

We have provided answers to some of the most frequently asked questions about COVID-19 vaccines. We update this page regularly (last updated 24 November 2021).

Refer also to COVID-19 and children: Frequently asked questions for answers to some of the commonly asked questions about COVID-19 in children, vaccines available in Australia, vaccine safety and schooling.

The Australian Government Department of Health website also has answers to commons questions about COVID-19 vaccines, which are available in 63 languages. Access these questions and answers here.

 

Questions about vaccination program

  • UPDATED - How many people in Australia have been vaccinated? 

    As of 22 November 2021, 38.4 million vaccine doses have been administered in Australia. Of those:

    • over 18.8 million people have had at least one dose 
    • over 17.5 million people are fully vaccinated 
    • 85.1% of people over the age of 16 years are fully vaccinated. 
       

    The number of doses administered is updated regularly and is available on the Australian Government Department of Health website.

  • Which COVID-19 vaccines are currently being used in Australia?

    The COVID-19 vaccines currently in use are:

    • Comirnaty (Pfizer vaccine), an mRNA vaccine. The  Pfizer vaccine is registered for use in people aged 12 years and older, and is currently the preferred COVID-19 vaccine brand for use in people under 60 years of age. 
    • COVID-19 Vaccine AstraZeneca (AstraZeneca vaccine), a viral vector vaccine. The AstraZeneca vaccine is registered for use in people aged 18 years and older. 
    • Spikevax (Moderna), an mRNA vaccine. The Moderna vaccine is registered for use in people aged 12 years and older. 

    The Australian Government has a fourth advance purchasing agreement for 51 million doses of Novavax’s NVX-CoV2373 COVID-19 vaccine, an adjuvanted protein vaccine. This agreement and rollout of vaccine will only proceed if the vaccine meets acceptable effectiveness and safety standards and is approved by the TGA.

    In addition, Australia is a member of the global COVAX Facility, which invests in COVID-19 vaccines and seeks to ensure they are distributed equitably across the world. Through the COVAX Facility, the Australian Government has made an upfront payment to secure enough doses for up to 50% of the Australian population to be vaccinated. Read more about the COVAX Facility here.

    More details on each vaccine and the number of vaccines procured by the government can be found here.

  • Who can get a COVID-19 vaccine?

    COVID-19 vaccine is currently recommended for all people aged 12 years and older.

    The COVID-19 Vaccine Clinic Finder can be used to find out when and where you can receive a COVID-19 vaccine. The Vaccine Clinic Finder provides information on what vaccines are recommended for you on the basis of your age.

  • Where can people access the vaccine, and is it free?

    COVID-19 vaccines are free for everyone aged 12 years and older in Australia, as per the Australian COVID-19 Vaccination Policy

    You do not need a Medicare card to receive the vaccine. The vaccine is available at general practices, community pharmacies, Commonwealth Vaccination Clinics, Aboriginal and Torres Strait Islander Community Controlled Health Services and state and territory vaccination hubs.

    To find a vaccination provider and book an appointment, visit the COVID-19 Vaccine Clinic Finder. The clinic finder is also available in 15 languages.

  • Is the COVID-19 vaccine mandatory?

    COVID-19 vaccination is mandatory for all providers of residential and in-home aged care.  From 17 September 2021, residential aged care workers are required to have at least one dose of a COVID-19 vaccine to enter a facility. Providers of residential and in-home care aged care must report weekly on the status of COVID-19 vaccinations and provide data on workers’ authorised exemptions to a COVID-19 vaccine. 
     
    COVID-19 vaccination has also been mandated for all quarantine workers, including all workers directly and indirectly involved in managed quarantine facilities and those involved in the transport of quarantined individuals. State and territory governments are responsible for addressing the mandated vaccination program for quarantine workers. 

    While for all other Australians COVID-19 vaccination currently 'is not mandatory and individuals may choose not to vaccinate', some states and territory governments have implemented COVID-19 vaccine mandates. Refer to your state or territory for information on vaccine requirements and public health orders.

  • What is herd immunity and how does it relate to the COVID-19 vaccination program?

    Herd immunity occurs when enough people in a population develop immunity, preferably from vaccination but also from natural infection, preventing the SARS-CoV-2 virus from easily spreading from person to person. 

    Achieving herd immunity usually requires a large proportion of the population to be vaccinated. The exact proportion of the population that need to be vaccinated to affect the spread of the SARS-CoV-2 virus depends on characteristics of the virus (e.g. how easily it is transmitted) and characteristics of the vaccine (e.g. its ability to stop transmission, and duration of protection). 

    It is easier to generate herd immunity with a vaccine that provides high level of long-term protection in most people and that prevents transmission of the infection between people. Vaccines that provide short-term protection require booster doses, making herd immunity harder to achieve. 

    Working out how many people in the population need to be vaccinated to reduce the spread of the virus is not easy to predict – it is best observed in ‘real time’. 

    As we learn more about the characteristics of COVID-19 vaccines and how well they protect against the disease and spread of the virus, many studies will be done to monitor how much impact the vaccines have and to what extent herd immunity is being developed over time. 

  • UPDATED - Which COVID-19 vaccines are already in use in other countries?

    As of 20 November 2021, over 7.69 billion doses of a COVID-19 vaccine have been given to people worldwide, the most common vaccines used to date are:

    • Vaxzevria (AstraZeneca), a viral vector vaccine (181  countries)
    • Comirnaty (Pfizer), an mRNA vaccine (149 countries)
    • Spikevax (Moderna), an mRNA vaccine (81 countries)
    • BBIBP-CorV (Beijing/Sinopharm), an inactivated vaccine (85 countries)
    • Sputnik V (Gamaleya), a viral vector vaccine (59 countries)
    • CoronaVac (Sinovac), an inactivated vaccine (45 countries)
    • Janssen/Johnson & Johnson vaccine (74 countries)

    Several other vaccines have been approved and are being used in other countries. More information about vaccine doses administered globally can be found at the London School of Hygiene COVID-19 vaccine tracker and at Our World in Data.

  • How are COVID-19 vaccination encounters recorded?

    It is mandatory to report all COVID-19 vaccines given to the Australian Immunisation Register (AIR). Information for providers about how to record and update immunisation details is available on the Services Australia website

  • How do I get a COVID-19 digital certificate or immunisation history statement to show proof of my COVID-19 vaccinations?

    If you are:

    • eligible for Medicare you can access the digital certificate or history statement via the Express Plus Medicare app, via your Medicare online account through myGov or through your My Health Record.
    • not eligible for Medicare, you can access your digital certificate using the Individual Healthcare Identifiers service (IHI service) through myGov. 
       

    Further information and instructions are available on the Services Australia website and the My Health Record website.

    Alternatively you can call the Australian Immunisation Register (AIR) on 1800 653 809 or ask your immunisation provider to print a statement for you.

  • Which COVID-19 vaccines used internationally are recognised in Australia and how can immunisation providers record these on the Australian Immunisation Register?

    The Therapeutic Goods Administration (TGA) has assessed the protection offered by certain COVID-19 vaccines that have been administered in other countries but are not yet registered in Australia. Coronavac (Sinovac), Covishield (AstraZeneca/Serum Institute of India), Covaxin (Bharat Biotech) and BBIBP-CorV (Sinopharm) are now considered recognised vaccines for incoming international travellers. People who have received two doses of these vaccines at the appropriate intervals will be regarded in Australia as appropriately vaccinated.

    Immunisation providers can now record these vaccines on an individual’s record on the Australian Immunisation Register (AIR) shortly. It is important that country of immunisation and batch number are recorded, as this information is needed to produce the International COVID-19 Digital Certificate.

    The TGA has advised that there are insufficient data to determine the protection of other vaccines at this time, including BIBP-CorV (Sinopharm), Covaxin (Bharat Biotech), Sputnik V (Gamaleya Institute) and Convidecia (CanSino). These vaccines may be recognised in the future as more data become available.
     
    A list of all vaccines currently able to be reported to AIR is available on the AIR vaccine code page. This page is updated regularly. COVID-19 vaccines are listed under the Non-standard vaccines section. It is important that provider's organisation is using the latest version of the practice management software to ensure the provider has the ability to record new vaccines as they become available. If lodging immunisation encounters using the AIR Site, the latest vaccines available will be presented for selection from the Vaccine/Brand field. More information about accessing the AIR site is available on How to set up your access to AIR.

Questions about getting vaccinated

  • UPDATED - Why should I get a COVID-19 vaccine?

    COVID-19 is a disease caused by the virus SARS-CoV-2. It can cause severe lung and generalised disease. As of 15 November 2021, it has caused over 5 million deaths worldwide, with more than 253 million cases reported.

    Although the elderly and people with underlying medical conditions are at the highest risk, anyone, including healthy young people, can get severe disease and die of COVID-19. In some people, COVID-19 may cause long-term symptoms of fatigue and breathlessness. We are still learning about other long-term complications caused by COVID-19. The virus is also easily spread by people with few or no symptoms; even if you may not become unwell with COVID-19, you may pass the virus on to others without knowing it and they may become very ill.  

    By vaccinating, you are protecting yourself and others from severe COVID-19. It is also likely that once a large proportion of the population is vaccinated, this will decrease the spread of COVID-19 in our community. 

  • What is Comirnaty (Pfizer vaccine) and how does it work?

    Comirnaty, also called BNT162b2, is a COVID-19 vaccine developed by Pfizer and BioNTech. It is an mRNA vaccine that contains the genetic code for an important part of the COVID-19 virus called the ‘spike protein’. After getting the injection, your body reads the genetic code and makes copies of the spike protein. Your immune system then detects these spike proteins and learns how to recognise and fight against COVID-19. The genetic code is quickly broken down and cleared away by the body. 

  • What is Spikevax (Moderna vaccine) and how does it work?

    Spikevax (Moderna vaccine) is a COVID-19 vaccine developed by Moderna. It is the second mRNA vaccine to receive provisional approval in Australia, following the Pfizer vaccine. It contains genetic code, called messenger RNA (mRNA), which instructs our body to make the unique spike protein from the COVID-19 virus. This trains our immune system to fight against COVID-19. Like the Pfizer vaccine, the mRNA from the Moderna vaccine does not change or interact with our DNA. 

  • What is Vaxzevria (AstraZeneca vaccine) and how does it work?

    Vaxzevria (AstraZeneca vaccine) is a COVID-19 vaccine developed by The University of Oxford and AstraZeneca. It contains the genetic code for an important part of the SARS-CoV-2 virus called the spike protein that is carried into your cells by a harmless common cold ‘carrier’ virus (an adenovirus). Your body then makes and uses the spike protein to learn to recognise and fight against SARS-CoV-2. The carrier adenovirus has been modified so that it cannot spread to other cells and cause infection. For this reason, the AstraZeneca vaccine does not behave like a ‘live vaccine’.

  • What are the differences between Pfizer, Moderna and AstraZeneca vaccines?

    A comparison of the three COVID-19 vaccines approved for use in Australia is presented below.

    Characteristic  Vaxzevria (COVID-19 vaccine AstraZeneca)  Comirnaty Spikevax 
    Sponsor AstraZeneca Pty Ltd  Pfizer Australia Pty Ltd Moderna Australia Pty Ltd
    Vaccine type Viral Vector mRNA mRNA
    Efficacy (After second dose) 62% to 73% 95% 94%
    Age indication  ≥18 years  ≥12 years  ≥12 years 
    Administration Route Intramuscular injection into deltoid muscle Intramuscular injection into deltoid muscle Intramuscular injection, preferably into deltoid muscle
    Schedule & Dose interval recommended by ATAGI  2 doses, 12 weeks apart (minimum interval 4 weeks)  2 doses, 3 to 6 weeks apart (21 to 42 days)  2 doses, 4 to 6 weeks apart (28 to 42 days) 
    Use of diluent  Not required  Required – dilute with sterile 0.9% NaCl without preservative  Not required 
    Dose volume  0.5mL  0.3mL (after dilution)  0.5mL 
    Volume per multi-dose vial  4mL or 5mL  0.45mL before dilution; 2.25mL after dilution)  5mL 
    Number of doses per vial*  8 doses in 4mL
    10 doses in 5mL 
     
    6 doses in 0.45mL 10 doses in 5mL
    Storage temperature in frozen state  Not stored in frozen state  -90°C to -60°C  -25°C to -15°C 
    Storage by provider (unused)  6 months at 2°C to 8°C  31 days at 2°C to 8°C 2 hours at 8°C to 30°C  30 days at 2°C to 8°C 24 hours at 8°C to 25°C 
    Thawing from frozen state  Not applicable  3 hours at 2°C to 8°C 30 min at room temperature  2.5 hours at 2°C to 8°C
    (Note: the thawing time at this temperature may be longer, up to 24 hours)1 1 hour at room temperature 
     
    Handling after thawing  Not applicable  Allow thawed vial to come to room temperature and gently invert it 10 times prior to dilution.  The vial should be swirled gently after thawing and before each withdrawal, but should not be shaken. 
    List of Ingredients 
    • Histidine
    • Histidine hydrochloride monohydrate\
    • Sodium chloride
    • Magnesium chloride hexahydrate
    • Disodium edetate (EDTA)
    • Sucrose
    • Ethanol absolute
    • Polysorbate 80
    • Water for injection
    • ((4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate) (ALC-0315)
    • 2-[(polyethylene glycol)-2000]-N,N-ditetradecylacetamide (ALC-0159)
    • Distearoylphosphatidylcholine (DSPC)
    • Cholesterol
    • Potassium chloride
    • Monobasic potassium phosphate
    • Sodium chloride
    • Dibasic sodium phosphate dihydrate
    • Sucrose
    • Water for injections
    • Heptadecan-9-yl 8-[2-hydroxyethyl-(6-oxo-6-undecoxyhexyl)amino]octanoate
    • Cholesterol
    • Distearoylphosphatidylcholine
    • 1,2-dimyristoyl-rac-glycero-3-methoxypolyethylene glycol-2000 (PEG2000-DMG)
    • Trometamol
    • Trometamol hydrochloride
    • Acetic acid
    • Sodium acetate trihydrate
    • Sucrose
    • Water for injection

     * Depending on the type of syringe and needle used, additional doses may be extracted. 

  • How many doses of COVID-19 vaccine are required and what is the schedule?

    The number and timing of doses differs depending on the brand of COVID-19 vaccine used. COVID-19 vaccines are not considered interchangeable, and whenever possible, the two-dose schedule should be completed with the same vaccine.

    The AstraZeneca vaccine requires two doses, recommended to be given 12 weeks apart, because the efficacy of the vaccine is highest with this interval between doses. The minimum interval is 4 weeks if required in certain circumstances. On 13 July 2021, ATAGI specifically recommended that in the current Delta outbreak situation an interval of between 4 and 8 weeks is preferred. People living in outbreak areas who received their first dose of COVID-19 Vaccine AstraZeneca more than 4 weeks ago should contact their vaccine provider to book their second dose as soon as possible. In non-outbreak settings, the preferred interval between doses of the AstraZeneca vaccine remains 12 weeks. 

    The Pfizer vaccine requires two doses, recommended to be given 3–6 weeks apart. 

    The Moderna vaccine requires two doses, recommended to be given 4-6 weeks apart.

    Administration of the Pfizer and Moderna vaccines using a 6-week interval, rather than 3 or 4, provides strong protection at the individual level but also allows for more people to be vaccinated with the first dose earlier. 

    The ATAGI clinical guidance on COVID-19 Vaccine in Australia in 2021 has further details on dose timing.

  • Will a booster dose of COVID-19 vaccine be required?

    In Australia, a single COVID-19 vaccine booster dose is now available for people aged 18 years and older, who received their second dose 6 or more months ago. There are some circumstances where the interval may be shortened to 5 months. Refer to the ATAGI Clinical Guidance for more information.

    The Pfizer vaccine is the recommended vaccine for a booster dose, even if you did not receive the Pfizer vaccine in the primary course, as it has been approved for use as booster by the TGA on 27 October 2021 and studies show its safety and effectiveness when used as a booster vaccine. The AstraZeneca vaccine can be used as a booster dose for people who received the AstraZeneca vaccine in their primary course or for those who are unable to receive the Pfizer vaccine. A decision about using the Moderna vaccine as a booster is expected at a later date. Further details are available in the ATAGI clinical guidance on COVID-19 Vaccine in Australia in 2021

    The Australian Technical Advisory Group on Immunisation (ATAGI) notes that those with risk factors for severe COVID-19 and those at increased occupational risk of COVID-19 will benefit most from a booster dose and are the highest priority. Refer to the ATAGI recommendation on the use of booster dose statement for more information on booster doses and who is at most risk of severe COVID-19. 

    Booster doses are also recommended for pregnant women aged 18 years and older who received their second dose of COVID-19 vaccine at least 6 months ago. The Pfizer vaccine is the preferred vaccine for pregnant women. 

    Booster doses are not currently recommended for people under the age of 18 years. 

    A third primary dose is recommended for people who are severely immunocompromised. This differs to a booster dose which is required when the vaccine effectiveness wanes overtime. A booster dose (i.e. fourth dose) is not yet recommended for people who are severely immunocompromised and have received a third primary dose. See Q&A on “Who is currently recommended to receive a third dose of a COVID-19 vaccine?”

     

  • Can I have the booster dose earlier than 6 months?

    Booster doses are recommended to be given at least 6 months after dose 2 of the primary course of COVID-19 vaccines. In special circumstances this may be shortened to no less than 5 months after the primary course, such as in remote areas or outreach vaccination programs or before overseas travel to a high-risk country.

  • Am I still considered ‘fully vaccinated’ if I don’t receive a booster dose after completing the primary course?

    Yes. A person is considered fully vaccinated after receiving two doses of the primary course at the recommended intervals. The exception to this is the Janssen-Cilag COVID-19 vaccine which is currently used overseas and is given as a single dose. See also 'How many doses of COVID-19 vaccine are required and what is the recommended schedule (including in an outbreak setting)?'

  • Who is currently recommended to receive a third dose of a COVID-19 vaccine?

    Australia has recommended a third primary dose of a COVID-19 vaccine in people who are severely immunocompromised, as they are more likely to have suboptimal response to the first two doses. This third dose differs from a booster dose which is required when protection from the initial doses has begun to decrease. People who are severely immunocompromised who receive a third dose are not yet recommended to receive a booster dose (i.e. fourth dose). Further information on booster doses in this population is expected. Refer to Box 1 in the ATAGI recommendation to see the list of conditions and therapies for which the third dose is recommended. The list of conditions and therapies was updated on 29 October 2021.

    The Pfizer or Moderna vaccine is preferred for the third dose as studies in immunocompromised people used mRNA vaccines. People who have had the AstraZeneca vaccine for the first two doses or people who have a contraindication to the Pfizer or Moderna vaccine can still have the AstraZeneca vaccine for their third dose. The recommended timing for a third dose is 2–6 months after the second dose. If the second dose was received over 6 months ago, the third dose can be given as soon as feasible.

  • What happens if the second dose is given early, late or is missed?

    If the second dose of the Pfizer, Moderna or AstraZeneca vaccine is given early (less than 14 days after the first dose), the dose is considered invalid. It is recommended that a replacement dose is given. The replacement dose can be given 4–12 weeks after the invalid dose. The interval is flexible and should be considered together with the risks and benefits of the individual. Refer to the ATAGI clinical guidance on COVID-19 vaccine in Australia in 2021 and ATAGI clinical advice on use of a different COVID-19 vaccine as the second dose for more information.

    If the second dose of either the Pfizer vaccine or the AstraZeneca vaccine is overdue (i.e. past the recommended interval), it should be given as soon as possible. A single dose likely only gives provide short-term protection. The second dose will be effective regardless of how late it is given. Even if the second dose is late, no vaccine doses need to be repeated.

  • Can COVID-19 vaccines be co-administered with other vaccines (eg, influenza vaccine)?

    A COVID-19 vaccine can be co-administered (i.e. given on the same day) with an influenza vaccine.  

    Routine administration of a COVID-19 vaccine on the same day as another vaccine, except for an influenza vaccine, can be done if required. However, there is currently limited evidence on the co-administration of a COVID-19 vaccine and other vaccines and so providers need to consider the need for co-administration and whether the vaccines can be given on separate visits. When vaccines are co-administered, there is the potential for an increase in mild to moderate adverse events. If co-administration or administration within a few days does occur, it could make it more difficult to attribute any adverse event that may arise.  

    This advice may change as further information becomes available. For more information, refer to ATAGI clinical guidance on COVID-19 Vaccine in Australia in 2021.

  • What activities can I do after vaccination?

    All regular daily activities can be performed after vaccination, including showering. If you feel well after vaccination, you can continue your usual exercise. If you feel unwell after vaccination (e.g. fever, body aches), you should take rest and seek medical attention for any symptoms you are worried about. For more information on some common side effects refer to the question "What are the likely side effects from COVID-19 vaccines".

  • How effective are COVID-19 vaccines?

    In clinical trials COVID-19 vaccines have been shown to provide excellent protection from getting sick with COVID-19. In these trials, after two doses the Pfizer vaccine was about 95% effective, the Moderna vaccine was 94% effective and the AstraZeneca vaccine was at least 62–70% effective at preventing people from getting sick with COVID-19. 

    There are ‘real world' studies (also called observational or post-market vaccine effectiveness studies) from vaccination programs in countries like the USA, the UK and Israel that show strong protection for both vaccines. These studies were conducted at the time the Delta variant was dominant.

    A large study from the UK found AstraZeneca to be 60% effective against COVID-19. Another study found 92% of people who were vaccinated were not hospitalised due to COVID-19.

    A study from the Netherlands found 94% of people who were vaccinated were not hospitalised due to COVID-19. 

    In a study from the US, the Pfizer vaccine was 80% effective and the Moderna vaccine was 95% effective at preventing hospitalisations due to COVID-19. Another study from the US found the Pfizer vaccine to be 42% effective and the Moderna vaccine to be 76% effective against COVID-19.

    A study from Qatar found 60% of people vaccinated with the Pfizer vaccine and 86% of people vaccinated with the Moderna vaccine were not infected with COVID-19. The same study found that the Pfizer vaccine was 97% effective and the Modern vaccine was 100% effective at preventing severe infection or death from COVID-19. As new variants of the virus emerge, information on the effectiveness against these variants will become available – refer to Will the COVID-19 vaccines be effective on new variants of the virus”. 

    The Novavax vaccine is about 89% effective at preventing people from getting sick with COVID-19, based on a press release from the company.
     

    The Novavax vaccine is about 89% effective at preventing people from getting sick with COVID-19, based on a press release from the company.

    At this stage it is unclear how long immunity from COVID-19 vaccines will last – refer also to What is herd immunity and how does it relate to the COVID-19 vaccination program?

  • How effective are COVID-19 vaccines in older adults?

    Studies from the UK, Canada and the USA show slightly reduced vaccine effectiveness (VE) against symptomatic infection and hospitalisation or death in older age groups, especially during the period when Delta variant was dominant.

    A study from Canada found that VE in adults aged 60 years and older was lower than in those aged 60 years and younger. VE against symptomatic infection was reported as 89% versus 92% for the Pfizer vaccine, 92% versus 96% for the Moderna vaccine and 81% versus 94% for the AstraZeneca vaccine. VE against hospitalisation and death was also lower in adults aged 60 years and older: 74% versus 89% for the Pfizer vaccine, 96% versus ~100% for the Moderna vaccine and 75% versus 96% for the AstraZeneca vaccine. 

    A UK study reported similar trends against symptomatic infections and severe disease by age and vaccine. VE against symptomatic infection from the Delta variant for those aged 65 years or older compared with those aged 16–39 was 59% versus 66% for the AstraZeneca vaccine and 80% versus 91% for the Pfizer vaccine. VE against hospitalisation was 92% versus 98% for the AstraZeneca vaccine and 98% versus 99% for the Pfizer vaccine. 

    Similarly, a study from the USA conducted during the Alpha and Delta periods showed the Pfizer and Moderna vaccines were 80% effective against hospitalisation in adults aged 65 years and older compared with 95% for those aged 18–64 years in the same study.

  • Will the COVID-19 vaccines be effective on new variants of the virus?

    Certain viruses, including the novel coronavirus, SARS-CoV-2, naturally mutate over time. Often these mutations don’t impact how viruses affect us. However, some recent variants of SARS-CoV-2 are more easily spread and appear to be associated with increased numbers of cases in some countries.

    Current evidence from clinical trials indicates that the antibodies induced from COVID-19 vaccines are likely to provide protection to a variety of mutations and minor changes. However, in some cases there may be an impact on how antibody developed from vaccines based on the original strain can ‘neutralise’ the virus. 

    There have been four variants of concern (VoC) since the start of the global COVID-19 pandemic. The WHO has classified them as Alpha, Beta, Gamma and Delta. They also monitor Variants of Interest (VoI) and Alerts for Further Monitoring.

    Currently approved vaccines have been shown to be effective to provide at least some protection against new variants as these vaccines work to create a broad immune response. The mutations causing these variants should not make the vaccines ineffective. 

     

  • How long will protection from the COVID-19 vaccine last?

    Currently, the evidence suggests that protection from COVID-19 vaccines lasts for at least 6 months. There is emerging evidence from real-world studies that suggests that protection from COVID-19 vaccines against infection reduces overtime, possibly from 6 months onwards. However, protection against severe disease, such as hospitalisation and death, has been shown to remain high 6 months after vaccination in many studies. COVID-19 booster vaccines have been recommended to address the reduction in protection over time. For more information, refer to Will a booster dose be required?

    Pfizer has announced that its vaccine provides immunity for at least 6 months. The Pfizer vaccine was found to be 91.3% effective against symptomatic COVID-19 up to 6  months after the second dose. Clinical trial data up to 6 months for the Moderna and AstraZeneca vaccines have not yet been announced.

     

  • UPDATED - Do the vaccines reduce the risk of transmission of SARS-CoV-2 to others?

    Data from the United Kingdom, the Netherlands and Spain show that the AstraZeneca, Pfizer and Moderna vaccines do reduce onward transmission of SARS-CoV-2 to a degree.

    Some early data are now available on the effectiveness of vaccines against transmission for the Delta variant. A recent study  from the UK found that full vaccination with the AstraZeneca and Pfizer vaccines reduced onward transmission against the Delta variant, but less than that for Alpha. In this study, two doses of the AstraZeneca vaccine reduced onward transmission by 36% for  the Delta variant compared with 63% for the Alpha variant, and full vaccination with two doses of the Pfizer vaccine reduced transmission by 74% for the Delta variant compared with 84% for Alpha.

    A study from the Netherlands also found that vaccination continues to reduce onward transmission. This study did not separate out the effectiveness by each vaccine (the Netherlands uses AstraZeneca, Pfizer, Moderna and Jansen vaccines), but when they compared the results to a previous study on transmission during the Alpha period, they found that onward transmission had increased by around 10% for the Delta variant. Both these studies also found that over time there was some waning in the effectiveness of vaccines against transmission.

    A study from Spain assessed the effectiveness of the COVID-19 vaccines at preventing onward transmission by measuring the vaccine effectiveness in people who were close contacts of infected individuals. The study found that the Moderna vaccine was 82% effective, the Pfizer vaccine was 69% effective and the AstraZeneca vaccine was 54% effective at preventing infection in people who were close contacts of COVID-19 infected individuals. 

     

  • What is ‘long COVID?’ Does the COVID-19 vaccine protect against ‘long COVID?’

    'Long COVID' is a condition where people with COVID-19 experience persistent symptoms that continue for at least 2 months. Common symptoms include fatigue, shortness of breath, cognitive dysfunction (‘brain fog’) and others. These symptoms generally affect the person’s everyday functioning. Symptoms can fluctuate or relapse over time. The World Health Organization has developed a case definition for this condition, also called ‘post COVID-19 condition’.

    Long COVID is still being studied, and no treatments are currently available. Vaccines are effective at preventing COVID-19 infection and, therefore, reduce the risk of long COVID. A study from the United Kingdom showed that compared with unvaccinated people, infected vaccinated people were less likely to experience symptoms for more than 28 days. 

  • Can I still get COVID-19 if I have been fully vaccinated?

    The COVID-19 vaccines available in Australia are very effective. Clinical trials and real world evidence have found that the vaccines are 70–95% effective in preventing people from getting sick with COVID-19. This means that people who are fully vaccinated are 70–95% less likely to get sick with COVID-19 compared with those who are not vaccinated, if they are exposed to the virus. However, a small proportion of fully vaccinated people may still get the disease. This does not mean the vaccines are not working. There are no vaccines, for any disease, that are 100% effective.

    Evidence from the United States suggests that fully vaccinated individuals who get infected with COVID-19 usually experience less severe symptoms than those who are unvaccinated.

  • Can I have a different COVID-19 vaccine for dose 1 and dose 2?

    In Australia, the Pfizer, Moderna and AstraZeneca vaccines require two doses of the same vaccine. ATAGI recommends completing the vaccination course with the same vaccine. There are some special circumstances where a mixed schedule may be is recommended. 

    These include:

    • anaphylaxis to the first dose of a COVID-19 vaccine 
    • thrombosis with thrombocytopenia following the first dose of AstraZeneca vaccine
    • any other serious side effect attributed to the first dose of a COVID-19 vaccine 
    • people who were partially vaccinated overseas with a COVID-19 vaccine not available in Australia.
       

    People who have had a first dose of the AstraZeneca vaccine and have one of the following conditions are recommended to receive the Pfizer or Moderna vaccine for their second dose:

    • history of cerebral venous sinus thrombosis (CVST) 
    • history of heparin-induced thrombocytopenia 
    • history of idiopathic splanchnic (mesenteric, portal, splenic) venous thrombosis 
    • history of anti-phospholipid syndrome (APLS) with thrombosis
    • history of capillary leak syndrome.

     

    There are emerging data to support the safety and effectiveness of mixed vaccine schedules (i.e. different vaccine brand for dose 1 and dose 2). A different brand can now be used for the second dose for other reasons such as being unable to access or not accepting a second dose of the same brand, although the same brand for dose 2 is preferred. For more information, refer to ATAGI clinical guidance on COVID-19 Vaccine in Australia in 2021.

     

  • Do I need the vaccine if I have already had COVID-19 in the past?

    Yes, COVID-19 vaccines are recommended for people with a past history of COVID-19. You do not need to delay vaccination if you have completely recovered from COVID-19. If a patient tests positive for COVID-19 between their first and second doses, the patient can receive their second dose once they have recovered from their acute illness, or defer for up to 6 months.

    The ATAGI clinical guidance on the use of COVID-19 vaccine in Australia in 2021 recommends people with SARS-CoV-2 infection can be vaccinated as soon as they have recovered from their acute illness or can defer vaccination for up to 6 months after onset of the SARS-CoV-2 infection. People who had an anti-SARS-CoV-2 monoclonal antibody or convalescent plasma treatment for COVID-19, such as sotrovimab or casirivimab+imdevimab, should wait at least 90 days before having a COVID-19 vaccine.

    COVID-19 vaccine clinical trials did include some people previously infected with the virus, although they had not reported it (they had a blood test showing past infection). These people had a good immune response to the vaccine and had similar mild and expected side effects to people who were not previously infected. This and other studies assessing vaccine safety in people who have previously been infected tell us that vaccinating someone after they had COVID-19 infection is safe.

    The healthcare professional can consult with a specialist immunisation service for additional advice if needed. If someone needs a temporary exemption from vaccination for work or other reasons as detailed in the ATAGI Expanded Guidance on temporary medical exemptions for COVID-19 vaccines, this can be obtained from their doctor using Commonwealth health department approved form, for up to 6 months.

  • What happens if I get COVID-19 between the first and second dose of a COVID-19 vaccine, or after the second dose and before a booster dose?

    Your body will develop an immune response within 2–3 weeks after the first dose and will be partially protected. However, all people need a second dose to achieve maximum and longer lasting protection. 

    If you are infected with COVID-19 and have only had one dose of vaccine, you will still be able to have the second dose of COVID-19 vaccine. You can receive your second dose once you have recovered from the acute illness, or defer for up to 6 months.   

    Some people may also develop COVID-19 disease after two doses;  however, evidence from the United States suggests that fully vaccinated individuals who get infected with COVID-19 usually experience less severe symptoms than those who are unvaccinated.

    If you develop COVID-19 disease after two doses, you can still receive the booster dose 6 months after the second dose. You can receive the booster dose once you have recovered from the acute illness or defer for another 6 months.

  • How do I prepare for COVID-19 vaccination and what to do after COVID-19 vaccination?

    Refer to the preparing for COVID-19 vaccination guide on what to do before your vaccination for what you should do before your COVID-19 vaccination as well as what to expect at your appointment.

    Refer to the after your COVID-19 vaccination guides  for a list of common side effects noted after each vaccine and what to do in the event of a side effect.

  • When preparing the Pfizer vaccine and leakage of diluent occurs, can the vaccine still be used?

    If there is a leakage of diluent from the vial during reconstitution of the Pfizer vaccine, you may use the vaccine if you have injected most of the diluent into the vial.

    Where you are uncertain about how much diluent you have injected, you may use the vaccine if you are able to draw up at least 4 doses. 

    Ensure that there has been no breach of infection control.

  • Can children have a COVID-19 vaccine?

    The TGA has provisionally approved both the Pfizer vaccine and the Moderna vaccine for use in people aged 12 years and older.

    Previously, the Pfizer vaccine was provisionally approved for use in people aged 16 years and older. Children and adolescents aged under 18 years cannot have the AstraZeneca vaccine.  

    On 27 August ATAGI extended its recommendation that all 12–15 year olds be vaccinated with the Pfizer vaccine, and on Monday 13 September all adolescents in this age group became eligible to receive COVID-19 vaccination.

    Adolescents aged 12–18 years are recommended to receive two doses of the Pfizer vaccine 21–42 days apart or two doses of the Moderna vaccine 28–42 days apart. Currently, people under 18 years of age are not recommended to receive a booster dose. For more information, refer to ‘Will a booster dose of COVID-19 vaccine be required?'

    Also refer to ‘How effective are COVID-19 vaccine in children?’ and ‘How safe are the COVID-19 vaccines in children?’

  • How effective are COVID-19 vaccines in children?

    The Pfizer and Moderna vaccines are highly effective in adolescents, and the Pfizer vaccine is highly effective in children aged 5–11 years. 

    clinical trial for the Pfizer vaccine found the vaccine to be 100% effective at preventing COVID-19 infection in adolescents aged 12–15 years. A trial for the Moderna vaccine found the vaccine to be 92% effective in preventing symptomatic COVID-19 infection in adolescents aged 12–17 years.

    Studies from the USA and Israel have also assessed the effectiveness of the Pfizer vaccine in adolescents aged 12–18 years, with the Israeli study finding the vaccine to be 90% effective at preventing COVID-19 infection and the US study finding the vaccine to be 93% effective at preventing hospitalisations in this age group. 

    The Pfizer vaccine data presented to the US Food and Drug Administration (FDA) showed the vaccine was 90% effective at preventing symptomatic COVID-19 infection in children aged 5–11 years. The vaccine was considered safe, with the majority of side effects considered mild to moderate and arising within the first 1 to 2 days, resolving shortly thereafter.  

    In Australia, the Pfizer and Moderna vaccines have been approved for use in people aged 12 years and older. Currently, children under 12 cannot have a COVID-19 vaccine; however, this is likely to change over time as more data from clinical trials in younger age groups become available and when the Therapeutic Goods Administration (TGA) approves the use of the vaccine in younger age groups.

  • Can I have a COVID-19 vaccine if I am pregnant, breastfeeding or planning pregnancy?

    Yes, the Pfizer and Moderna vaccines are now routinely recommended for pregnant women, and pregnant women are now a priority population for vaccination. This is a joint recommendation from the Australian Technical Advisory Group on Immunisation and the Royal Australian and New Zealand College of Obstetricians and Gynaecologists

    Booster doses are also recommended for pregnant women aged 18 years and older who received the second dose of their primary vaccination at least 6 months earlier. The Pfizer vaccine is the preferred vaccine for pregnant women. For more information, refer to the ATAGI clinical guidance

    The recommendation to use the Pfizer vaccine or the Moderna vaccine is based on the availability of more safety data for these vaccines in pregnant women, whereas there is very limited evidence using the AstraZeneca vaccine during pregnancy. However, if the Pfizer vaccine or Moderna vaccine is not available, the AstraZeneca vaccine can be considered by pregnant women if the benefits of vaccination outweigh the risks for the individual, such as in outbreak settings. 

    The Pfizer vaccine and Moderna vaccine continue to be the preferred vaccines for people under 60 years of age, including women who are breastfeeding and planning pregnancy. However, if the Pfizer or Moderna vaccine is not available, the AstraZeneca vaccine can be given to women who are breastfeeding or planning pregnancy if the benefits of vaccination outweigh the risks for the individual. There are no theoretical safety concerns regarding use of the AstraZeneca vaccine in these individuals. 

    Women who are breastfeeding do not need to stop breastfeeding after vaccination. Women who are planning pregnancy do not need to avoid becoming pregnant after vaccination. Research has shown that pregnant women have a higher risk of severe illness from COVID-19, and compared with non-pregnant women with COVID-19 they are more likely to need admission to an intensive care unit and mechanical ventilation. They are also more likely to deliver their babies early, and their babies are more likely to require admission to a newborn intensive care unit. 

    There is now real-world evidence from countries such as the USA showing that mRNA vaccines (such as the Pfizer vaccine and the Moderna vaccine) are safe in pregnant women, and the side effects they report are similar to those in non-pregnant women. 

    Women who received their first dose of the AstraZeneca vaccine and are pregnant can receive dose 2 of either the AstraZeneca vaccine or the Pfizer or Moderna vaccine, although an mRNA vaccine (Pfizer or Moderna) is preferred. See also “I had dose one of the AstraZeneca vaccine and am now pregnant. What is the advice for dose 2”.

    More information is available in the COVID-19 vaccination decision guide for women who are pregnant, breastfeeding or planning pregnancy.

  • I had dose one of the AstraZeneca vaccine and am now pregnant. What is the advice for dose 2?

    Women who received their first dose of the AstraZeneca vaccine and are pregnant can receive dose two of either the AstraZeneca vaccine, or Pfizer or Moderna vaccine, although an mRNA vaccine (Pfizer or Moderna) is preferred. Pregnant women should speak with their healthcare provider about the best choice for them.

    Providers and consumers may wish to consider:

    • there is a growing body of evidence supporting the safety of mRNA vaccines in pregnancy
    • there are still very limited data on the safety of viral vector vaccines (such as the AstraZeneca vaccine) in pregnancy
    • there are comparatively less data on the safety and efficacy of mixed vaccine schedules than completing the series with the same vaccine.
       
  • Can I have a COVID-19 vaccine if I am immunocompromised?

    Being immunocompromised means you have a weakened immune system, either from an underlying medical condition or from medical treatment that weakens your immune system. 

    If you are immunocompromised, you are strongly recommended to receive a COVID-19 vaccine currently approved in Australia – the Pfizer, Moderna or the AstraZeneca vaccine. The ATAGI clinical guidance on COVID-19 Vaccine in Australia in 2021 provides a list of medical conditions associated with increased risk of severe COVID-19 illness. In addition, a third primary dose is now recommended for people who are severely immunocompromised. This differs from a booster dose which is required when the vaccine effectiveness wanes overtime. A booster dose (i.e. fourth dose) is not yet recommended for people who are severely immunocompromised and have received a third primary dose. For more information, refer to 'Who is currently recommended to receive a third dose of a COVID-19 vaccine' and 'Will a booster dose of COVID-19 be required?'

    All of these vaccines are considered to be safe in immunocompromised people. However, they may be less effective in immunocompromised people, because the vaccines rely on your immune system to build a response. This means that it’s important to continue other protective measures against COVID-19, even if you are vaccinated. 

    The Pfizer vaccine and the Moderna vaccine are not live vaccines. The AstraZeneca vaccine contains a virus that is non-replicating and is also not considered to be a live vaccine, meaning that it cannot cause infection even in an immunocompromised person.

    If you are taking an immune-weakening treatment (immunosuppressant/immunomodulator), including chemotherapy, you should discuss the best timing of vaccination with your treating doctor. 

    For more information, refer to the COVID-19 vaccination – Shared decision making guide for people with immunocompromise.

  • Could the vaccine react with other medications? Do other medications need to be stopped to have a COVID-19 vaccine?

    No, in most cases medication should not be stopped before having a vaccine. There are a few situations in which people might be advised to either delay vaccination or delay a particular medication:

    • Some people taking blood thinners (anticoagulants) may be advised to delay vaccination if there is a high risk of bleeding after the vaccine is injected. Most people on a stable dose of blood thinner will be able to receive the vaccine without any change to their medication.
    • People taking immune-weakening treatments (immunosuppressants), including chemotherapy, should discuss the best timing of vaccination with their treating doctor. 
       

    People taking other medications should continue their regular treatment before and after vaccination. 
     

  • I have heard that there are treatments for COVID-19 such as sotrovimab. What are these treatments and when can they be used?

    Vaccination is the safest and most important way to be protected from COVID-19. For people who become infected with COVID-19 and are at risk of severe disease, the TGA has granted provisional approval for the use of three treatments:

     

    Sotrovimab and casirivimab + imdevimab are monoclonal antibody treatments for adults and adolescents (aged 12 years and older weighing at least 40 kg) who become infected with COVID-19 and are at higher risk of hospitalisation. This includes older Australians and those with risk factors for severe disease. These treatments are given by intravenous infusion.

    Remdesivir is an antiviral treatment option for adults and adolescents (aged 12 years and older weighing at least 40 kg) suffering from severe COVID-19 infection, in hospital care and requiring oxygen support. It is given by intravenous infusion.

  • Can I have a COVID-19 vaccine if I have anti-SARS-CoV-2 monoclonal antibody or convalescent plasma treatment?

    People who have had an anti-SARS-CoV-2 monoclonal antibody or convalescent plasma treatment, such as sotrovimab or casirivimab+imdevimab, should wait at least 90 days before having a COVID-19 vaccine.

Questions about vaccine safety - General

  • Can you get COVID-19 from a COVID-19 vaccine?

    No, you cannot get COVID-19 from a COVID-19 vaccine. 

    To get COVID-19, a live virus that can multiply in your body has to infect you. No vaccine supplied currently in the world contains live SARS-CoV-2 virus. 

    The vaccines available in Australia and elsewhere contain a genetic material that codes for the spike protein (eg, Pfizer, Moderna and AstraZeneca), the spike protein itself (eg, Novavax) or an inactivated (or killed) form of the virus (in vaccines manufactured in China). They do not contain any live SARS-CoV-2 virus. 

  • What are the likely side effects from COVID-19 vaccines?

    All vaccines can cause side effects. Usually these are mild and temporary. Clinical trials of COVID-19 vaccines have reported side effects such as pain at the injection site, fever or muscle aches starting on the day or day after vaccination and go away without treatment.  

    The most common side effects for both vaccines include pain at the injection site, tiredness, headache, muscle pain, chills, joint pain and fever. These side effects are temporary and go away without treatment in 1–2 days. Sometimes these flu-like side effects can mean people don’t carry out their usual activities for a day or so. 

    For more detailed information about the side effects of each vaccine, refer to:

     

    AusVaxSafety is actively monitoring the side effects reported after COVID-19 vaccines in Australia. The surveillance data report is updated weekly.

  • What should I do if I have side effects after a COVID-19 vaccine?

    Common side effects include pain, redness or swelling at the site of your injection, as well as tiredness, headache or fever. You can take paracetamol or ibuprofen to help with side effects like pain, headache or fever. 

    These short-term side effects are expected and reflect a developing immune response to vaccination. If you have significant side effects (such as fever, tiredness or muscle aches) which are preventing you from carrying out your usual activities, you may need to take extra rest until you feel better. 

    You should seek urgent medical assistance (e.g. by calling 000) if you think you are having a severe allergic reaction, such as if you are experiencing difficulty breathing, hives, lip swelling or feeling faint.

    You should seek advice from your usual healthcare provider (e.g. GP) if you have any side effects that you are concerned about, or if your side effects have not gone away after a few days. 

    Be aware of the very rare possibility of serious symptoms after AstraZeneca vaccine caused by TTS. These symptoms may include new onset severe headache or abdominal pain starting in the 4-42 days after vaccination. Be sure to seek medical attention if you have any concerns (refer also to the question What are the symptoms of thrombosis with thrombocytopenia syndrome (TTS)?)

    You can report potential side effects after vaccination to your state or territory health authority, or directly to the Therapeutic Goods Administration (TGA). Your healthcare provider can make the report for you if you wish. This will help the TGA collect information about adverse effects that occur after COVID-19 vaccination and detect any possible unexpected safety signals.

  • If I have side effects after the first dose of a COVID-19 vaccine, can I still have the second dose?

    Yes, almost always. Side effects such as pain at the injection site, fever, chills, tiredness, headache and muscle aches occur commonly after the first dose of a COVID-19. You should have the second dose even if you experienced these side effects.

    These side effects are caused by your immune system responding appropriately to the vaccine. Although they cause discomfort and inconvenience, they are usually brief and go away within a few days. Some people may need to take paracetamol or ibuprofen to help reduce the discomfort. You may also need to take extra rest in the day or so after vaccination, until you feel better.

    Having the second dose is important to ensure you get the best possible protection against COVID-19.  

    If you have had a severe allergic reaction to your first dose, or any other severe symptoms that you are worried about or have been diagnosed with TTS after the AstraZeneca vaccine, discuss these with your healthcare provider before having the second dose.

  • How can I report a potential side effect after immunisation?

    If you have any side effects that are unexpected, severe, or which you are concerned about, you can report them to your state or territory health authority, or directly to the Therapeutic Goods Administration (TGA). Your healthcare provider can make the report for you if you wish. This will help the TGA collect information about adverse effects that occur after COVID-19 vaccination and detect any possible unexpected safety signals. 

    For information on how to make the report, refer to the TGA webpage Reporting suspected side effects associated with a COVID-19 vaccine
     

  • How safe are the COVID-19 vaccines for children?

    Clinical trials have shown that the Pfizer and Moderna vaccines are safe for children aged ≥12 years, and data are becoming available for younger age groups too.

    In the clinical trials of the Pfizer and Moderna vaccines, adverse events following COVID-19 vaccination in children were mild and generally resolved within 1 to 2 days. Pain at the injection site was the most common side effect in children aged 12–15 years. Side effects such as fatigue, fever, headache and chills were more common after the second dose than the first dose of the vaccine. Overall the frequency and types of side effects were similar to those seen in people aged 16–50 years.

    These side effects are expected and reflect a developing immune response to vaccination. For more information refer to ‘What should I do if I have side effects after a COVID-19 vaccine?’

    A risk of myocarditis and pericarditis has been seen in people who have had mRNA vaccines (including the Pfizer vaccine and the Moderna vaccine) overseas. These cases have been reported more commonly in people aged under 30 years, including in adolescents. For more information refer to ‘What is myocarditis and pericarditis?' and 'Can the Pfizer and Moderna vaccine lead to myocarditis and pericarditis?’

  • Are COVID-19 vaccines safe for people with a disability?

    All three COVID-19 vaccines available in Australia are safe for people with a disability, including people with autism. People with a disability are at risk of severe SAR-COV-2 infection and are encouraged to receive COVID-19 vaccination. Vaccination will not only prevent people with a disability from getting sick from COVID-19 but will also protect others from getting infected by preventing the spread of the virus.

    A list of vaccination hubs for people with a disability and more information can be found here.

  • Do COVID-19 vaccines used in Australia contain pork gelatine?

    The Pfizer, Moderna and AstraZeneca vaccines do not contain any pork gelatine. 

    A list of ingredients for the Pfizer vaccine, the Moderna vaccine and the AstraZeneca vaccine has been published. Once other vaccines are approved for use in Australia, their list of ingredients will be available.

    The Australian National Imams Council and the Muslim Health Professional Australia both have endorsed the COVID-19 vaccines in Australia. They confirmed that the COVID-19 vaccines do not contain any prohibited substances and are considered safe.

    The NSW Jewish Board of Deputies also encourages the Jewish community to receive COVID-19 vaccination. 

  • Do COVID-19 vaccines used in Australia contain material from aborted fetuses?

    There are no cells from aborted tissue in any COVID-19 vaccine. The AstraZeneca vaccine is manufactured using material originally sourced from a human embryo (Human Embryonic Kidney cells: HEK293). Fetal cell lines were not used in the development or manufacturing of the Pfizer and Moderna vaccines, but they were used during the testing stages of the vaccine. 

  • Is the mRNA in some COVID-19 vaccines harmful?

    Some COVID-19 vaccines, including the Pfizer vaccine and the Moderna vaccine, contain mRNA, a form of genetic code. This mRNA contains the code for an important part of the SARS-CoV-2 virus called the ‘spike protein’. After vaccination, our cells make some copies of the spike protein, and this trains our immune system to recognise and fight against SARS-CoV-2. mRNA is very fragile and gets broken down and removed very quickly and easily by our body. 

    mRNA vaccines such as the Pfizer vaccine and the Moderna vaccine have been given to tens of millions of people around the world, and have been safe and well tolerated. 

    The only serious side effect that has been confirmed to be caused by an mRNA vaccine is anaphylaxis, a type of serious allergic reaction, which can occur after any vaccine or medicine, and which is treatable.

    Anaphylaxis after an mRNA vaccine is still very rare. The rate of anaphylaxis after the Pfizer vaccine in the USA as of December 2020 was 11.1 cases per million people and the rate after the Moderna vaccine as of January 2021 was 2.5 cases per million people. 

  • Does the AstraZeneca vaccine contain a live virus?

    No. The AstraZeneca vaccine contains a harmless ‘common cold’ virus (an adenovirus) that carries the piece of genetic code for the SARS-CoV-2 spike protein into your cells. This adenovirus has been modified so that it can only enter your cells once, and it cannot replicate and spread to other cells. It therefore cannot cause infection, and does not behave like a ‘live vaccine’. It is considered safe for people who cannot have live vaccines, such as people with immunocompromise (weakened immune systems). 

  • How is vaccine safety monitored after a vaccine is approved for use?

    After any vaccine is registered and it starts to be given to people, vaccination experts and regulators continue to monitor vaccine safety in several ways. People can report side effects or adverse events directly to the regulatory body, the TGA. This is called passive surveillance because it waits for people to report. As a further check, the TGA assesses the quality of every batch of vaccine before it can be supplied in Australia.

    Weekly TGA reports on COVID-19 vaccine safety monitoring are published here.

    There is also active surveillance where researchers or regulators actively seek out any side effects in large groups of people given the vaccine. One form of active surveillance is where researchers continue to study the vaccine’s effectiveness and safety (sometimes called ‘phase 4’ trials). Another form is using established systems such as AusVaxSafety, in which clinics send SMS messages to people receiving vaccines (or their parents or carers) to ask if they had any reactions after receiving a vaccine. Independent experts analyse the responses to make sure that any safety issues are detected quickly. AusVaxSafety operates in almost 300 clinics around Australia and cover hundreds of thousands of people, and safety monitoring data are published weekly here.


    The systems described above will be used and expanded to monitor vaccine safety for all licensed COVID-19 vaccines, with experts meeting to review all reported data even more frequently than for usual vaccines.

  • Can COVID-19 vaccines lead to infertility?

    No, there is no evidence that any of the three COVID-19 vaccines being used in the Australian COVID-19 vaccination program can lead to infertility. 

    Before human trials, the PfizerModerna and AstraZeneca vaccines were assessed for their effect on fertility in animal studies. These studies found pregnancy rates in animals that received the vaccine were same as for those that did not receive the vaccine.

    Two studies from Israel assessed fertility in women who were undergoing in vitro fertilisation (IVF) or intracytoplasmatic sperm injection (ICSI) and had received the Pfizer vaccine. Two further studies from the United States and Israel assessed people who underwent IVF and received mRNA vaccines (Pfizer or Moderna). These four studies found that mRNA vaccines did not affect the quality and number of eggs women produced, the rate at which eggs were successfully fertilised, the number of embryos resulting from fertilisation that were of good quality, or the pregnancy rate that resulted from treatment. Given that the Pfizer and Moderna vaccines did not affect fertility treatment, this implies that the vaccines do not lead to infertility.

    A study in men receiving either the Pfizer and Moderna vaccine and a second study in men receiving the Pfizer vaccine found that the volume and quality of sperms did not change after they received either mRNA vaccine in healthy men or in men who had decreased fertility.

    Pregnant people are a priority group for COVID-19 vaccination, and the Pfizer vaccine or Moderna vaccine is recommended at any stage of pregnancy, due to age. Women who are breastfeeding or planning pregnancy are also recommended to receive these vaccines and women who are trying to become pregnant do not need to delay vaccination or avoid becoming pregnant after vaccination. The COVID-19 vaccination decision guide for people who are pregnant, breastfeeding or planning pregnancy is available on the Department of Health website.

  • Can I have a COVID-19 vaccine if I have dermal fillers?

    Yes, COVID-19 vaccines are recommended if you have dermal fillers.

    There have been reports of facial swelling following mRNA vaccinations in people with a history of injections with dermal facial fillers. In the clinical trial of the Moderna vaccine, two participants who had dermal facial fillers experienced facial swelling within 2 days of vaccination. Potential swelling of the face in people who had dermal fillers has been added as a side effect to the Moderna product information. The swelling is short-lived and a common side effect of dermal fillers.

    In Europe, the European Medicines Agency (EMA) assessed cases of facial swelling in people with a history of injections with dermal facial fillers after receiving the Pfizer vaccine, Facial swelling has been added as a side effect to the Pfizer vaccine in the European product information. 

    COVID-19 vaccines are still recommended in people with a history of dermal fillers. If you have any concerns, speak to your treating doctor.

    The AstraZeneca vaccine is not known to be associated with facial swelling in people with a history of dermal fillers. 

Questions about vaccine safety - Thrombosis with thrombocytopenia (TTS)

  • UPDATED - Does the AstraZeneca vaccine lead to blood clots?

    Yes, but very rarely. The AstraZeneca vaccine is associated with a very rare risk of a condition called thrombosis with thrombocytopenia syndrome, or TTS.

    TTS involves blood clots (thrombosis) along with low blood platelet levels (thrombocytopenia), and occurs around 4-28 days after vaccination. As at 17 November 2021 it is estimated to affect estimated to affect around 2.4 per 100,000 doses in Australia. To date, the great majority of cases were after the first dose of the vaccine. 

    The Pfizer vaccine and the Moderna vaccine are not associated with a risk of TTS. 

    Not all clots that occur after having the AstraZeneca vaccine will be due to TTS. Other blood clotting problems occur commonly in the population. Annually, common clots such as deep vein thrombosis or pulmonary embolism (a clot in the lungs) will affect about 1 in a 1,000 people in Australia, unrelated to any vaccine.

    TTS is a unique, new condition that requires certain blood tests to confirm it. 

  • Who is at risk of getting thrombosis with thrombocytopenia syndrome (TTS)?

    Younger adults (i.e. under 60 years of age) appear to have a higher risk of thrombosis with thrombocytopenia syndrome (TTS) than older adults. No other specific factors (such as pre-existing medical conditions) have been linked to, or found to predict, the likelihood of this condition occurring. 

    More cases of TTS have been reported in women, but it is not yet clear if sex is a risk factor. More women than men have been vaccinated in many of the countries using the AstraZeneca vaccine, since women make up a large proportion of frontline healthcare workers and who have been prioritised for vaccination.

  • If I have a history of blood clots or an increased risk of clotting, can I still have the AstraZeneca vaccine?

    Most people who have had blood clots in the past, or who have an increased risk of blood clots, can still have the AstraZeneca vaccine. This is because the vaccine does not increase the overall risk of blood clots. People with a history of the following conditions can receive the AstraZeneca vaccine:

    • deep vein thrombosis or DVT (a type of blood clot usually in the leg or arm)
    • pulmonary embolism (a type of blood clot in the lungs)
    • stroke
    • heart attack
    • a family history of blood clots
    • current or past thrombocytopenia (low platelet count)
    • those taking an anticoagulant medication. 

    These conditions do not increase the risk of TTS. 

    If you have an increased clotting tendency, talk to your doctor before having the AstraZeneca vaccine. The AstraZeneca vaccine is safe for people with clotting tendencies that are not immune-mediated. This includes conditions such as Factor V Leiden. 

    If you have had one of the following rare, specific causes of blood clots, you are recommended to have the Pfizer or Moderna vaccine instead of the AstraZeneca vaccine:

    • a clot in a blood vessel in the brain, called cerebral venous sinus thrombosis 
    • a type of blood clot in the abdomen (i.e. in the splanchnic circulation, which includes the mesenteric, portal or splenic veins), without any other known cause (i.e. idiopathic)
    • a condition called ‘heparin induced thrombocytopenia’, which is a reaction to the medicine heparin
    • a blood clot associated with antiphospholipid syndrome.

    There is a theoretical concern that the above conditions may increase the risk of TTS. 
     

  • Why are Pfizer and Moderna vaccines now preferred for people under 60 years of age?

    The Pfizer and Moderna vaccines are recommended as the preferred vaccine over the AstraZeneca vaccine for people under 60 years of age on the basis of an assessment of benefits and risks. While thrombosis with thrombocytopenia syndrome (TTS) is very rare overall, it appears to be more common in younger adults than in older adults. 

    For adults 60 years of age and older, the benefits of vaccination with the AstraZeneca vaccine greatly outweigh the risks because this age group has a lower risk of TTS but have a higher risk of severe disease and death from COVID-19. Adults 60 years of age and older can still receive the Pfizer or Moderna vaccine when available.

    In outbreak areas, the benefits of vaccination with the AstraZeneca vaccine are greater than the risk for all people, including people under 60 years of age. People aged 60 years and under can receive the AstraZeneca vaccine in an outbreak setting.

    Similarly, the risk-benefit balance will be different for different countries, depending on their local rates of COVID-19.

    People under 60 years of age can still choose to have the AstraZeneca vaccine if the benefits of vaccination clearly outweigh the risk for them personally and they provide informed consent. 

    For further information on weighing up the risks and benefits refer to COVID-19 vaccination – Weighing up the potential benefits against risk of harm from COVID-19 Vaccine AstraZeneca document. 

  • Why should we still use the AstraZeneca vaccine now that we know about thrombosis with thrombocytopenia syndrome (TTS)?

    All medicines and vaccines can be associated with rare side effects. We have to balance the potential risk of a serious side effect with the benefits of each medicine or vaccine we take. 

    There is an ongoing threat of COVID-19 in Australia and a clear need to have as many people living in Australia vaccinated as practical. Vaccination helps both individuals and the community to be protected.

    We also will not be able to avoid restrictions, begin to open borders, have Australians return home or return to a more usual way of life until a great portion of our community is vaccinated. 

    The AstraZeneca vaccine is recommended for people age 60 years and older.

    The Pfizer vaccine and the Moderna vaccine are preferred for adults under the age of 60 years. In outbreak settings, people 60 years and younger who do not have immediate access to the Pfizer vaccine or the Moderna vaccine should strongly consider vaccination with the AstraZeneca vaccine. 

  • Where can providers find information about thrombosis with thrombocytopenia syndrome (TTS)?
  • What are the symptoms of thrombosis with thrombocytopenia syndrome (TTS)?

    The symptoms of thrombosis with thrombocytopenia syndrome (TTS) can vary depending on the location and extent of the blood clot. Possible symptoms include:

    • severe, new and persistent headache which is not getting better with simple painkillers and may be worse when lying down
    • nausea and vomiting
    • blurred vision, seizures, difficulty speaking or drowsiness
    • new chest pain or difficulty breathing
    • abdominal pain associated with feeling unwell
    • tiny blood spots under the skin 

    The symptoms are most likely to appear between 4 and 28 days after vaccination with the AstraZeneca vaccine. TTS can cause serious illness, disability or even death. Anyone who has concerning symptoms after vaccination, such as those listed above, should seek medical care urgently. 

    For further information, read the Department of Health’s patient information sheet on AstraZeneca vaccine and thrombosis with thrombocytopenia syndrome.

  • Is thrombosis with thrombocytopenia syndrome (TTS) curable?

    Thrombosis with thrombocytopenia syndrome (TTS) is a newly discovered but rare condition that can occur rarely at around 4-42 days after vaccination with the AstraZeneca vaccine. Specialists have already developed specific ways to treat it, including treatments such as anticoagulant medication (other than heparin), intravenous immunoglobulin (an antibody infusion) and prednisolone (a steroid). 

    Of the TTS cases reported in the UK, more than 80% of people who had TTS survived, and 18% unfortunately died. Now that doctors are better able to recognise and treat TTS early, it is hoped that the survival rate will improve. 

    Of note, some of the recent cases of TTS reported to the TGA that have been linked to the AstraZeneca vaccine have been milder than those first recognised.

  • Can I have a COVID-19 vaccine if I have a history of blood clots?

    Most people who have had blood clots in the past, or who have an increased risk of blood clots, can still have COVID-19 Vaccine AstraZeneca. This is because the vaccine does not increase the overall risk of blood clots. People with a history of the following conditions can receive the AstraZeneca vaccine:

    • deep vein thrombosis or DVT (a type of blood clot usually in the leg or arm)
    • pulmonary embolism (a type of blood clot in the lungs)
    • stroke
    • heart attack
    • a family history of blood clots
    • current or past thrombocytopenia (low platelet count)
    • those taking an anticoagulant medication 

    These conditions do not increase the risk of TTS. 

    If you have an increased clotting tendency, talk to your doctor before having the AstraZeneca vaccine. The AstraZeneca vaccine is safe for people with clotting tendencies that are not immune-mediated. This includes conditions such as Factor V Leiden. 

    If you have had one of the following rare, specific causes of blood clots, you are recommended to have the Pfizer vaccine instead of the AstraZeneca vaccine:

    • a clot in a blood vessel in the brain, called cerebral venous sinus thrombosis 
    • a type of blood clot in the abdomen (i.e. in the splanchnic circulation, which includes the mesenteric, portal or splenic veins), without any other known cause (i.e. idiopathic)
    • a condition called ‘heparin induced thrombocytopenia’, which is a reaction to the medicine heparin
    • a blood clot associated with antiphospholipid syndrome.

    There is a theoretical concern that the above conditions may increase the risk of TTS. 

  • Are there any medications known to increase the risk of thrombosis with thrombocytopenia syndrome (TTS)?

    No, it is not yet known whether any medications increase the risk of thrombosis with thrombocytopenia syndrome (TTS). This includes medications such as aspirin and other anti-platelet drugs, heparin or low molecular weight heparin. There are no specific theoretical safety concerns for these drugs. 

    There are three published case series (123) of patients who had TTS after AstraZeneca vaccine, and in both case series, no patient had a history of exposure to heparin. 

  • UPDATED - If I’ve already had my first dose of AstraZeneca vaccine, can I still have the second dose?

    Thrombosis with thrombocytopenia syndrome (TTS) has predominantly been reported after a first dose of the AstraZeneca vaccine. The risk is much lower after the second dose. In the UK, 46 cases of TTS have been reported out of the 24.8 million second doses given of the AstraZeneca vaccine.

    People who have had their first dose of the AstraZeneca vaccine without any serious side effects can have the second dose. This includes people under 60 years of age.

    Women who received their first dose of the AstraZeneca vaccine and are pregnant can receive dose two of either the AstraZeneca vaccine or the Pfizer vaccine, although the Pfizer or Moderna vaccine is preferred.

    People who have had their first dose of the AstraZeneca vaccine and are subsequently found to have had a past history of heparin-induced thrombocytopenia (HIT), cerebral venous sinus thrombosis (CVST), splanchnic (mesenteric, splenic, portal) thrombosis or antiphospholipid syndrome with thrombosis are recommended to receive the Pfizer or Moderna vaccine for their second dose. 

    People who have had a blood clot associated with low platelet counts after their first dose of the AstraZeneca vaccine should not have the second dose. If you’re unsure about the second dose, talk to your healthcare provider to help you weigh up the risks and benefits.

    ATAGI recommends that the same COVID-19 vaccine brand should be used for the primary course; however, in some circumstances, like not being able to access or not accepting of the brand, a different brand can be used for dose two.

  • Can I take heparin if I’ve had the AstraZeneca vaccine?

    Yes, there is no evidence that exposure to heparin increases the risk of TTS.

  • Can I have the AstraZeneca vaccine if I’ve recently been given heparin?

    Yes, there is no evidence that exposure to heparin increases the risk of TTS.

  • If I’ve had a blood clot recently, how long should I wait before having the AstraZeneca vaccine?

    It’s recommended to wait around a week, particularly if you’ve been started on anticoagulation treatment, just to make sure your treatment is stable. As for any other vaccine, vaccination should be deferred until you feel well and have recovered from any acute illness. 

Questions about vaccine safety - other conditions

  • Can I have a COVID-19 vaccine if I have allergies?

    Almost all people with allergies can have a COVID-19 vaccine. This includes people with food allergies, asthma or hay fever. 

    People who have had anaphylaxis (a type of severe allergic reaction) to a particular COVID-19 vaccine, or to an ingredient of a COVID-19 vaccine, should not have another dose of that vaccine. They may be able to have an alternative brand of COVID-19 vaccine.

    For some people, precautions may be needed before vaccination, such as consulting an allergy specialist, being vaccinated in a facility which has medical staff and being observed for at least 30 minutes after vaccination.

    This applies to people in the following groups:

    • people who have had a suspected allergic reaction after a dose of a COVID-19 vaccine 
    • people who have had an allergic reaction (but not anaphylaxis) to an ingredient of a COVID-19 vaccine
    • people who have had anaphylaxis to other vaccines or to medications (including injectable or oral medications) where there may be common ingredients with a COVID-19 vaccine (such as polyethylene glycol, an ingredient in the Pfizer vaccine or the Moderna vaccine, or polysorbate 80, an ingredient in the AstraZeneca vaccine 
    • people with a history of confirmed mastocytosis (a mast cell disorder) with recurrent anaphylaxis, and who require treatment for this condition.
  • If I have an allergic reaction after a COVID-19 vaccine or to one of its ingredients, can I still have the second dose?

    If you have had anaphylaxis (a type of severe allergic reaction) to a previous dose of a COVID-19, or to one of its ingredients, you should not have that vaccine again. Your healthcare provider can help to determine whether it will be safe for you to have an alternative COVID-19 vaccine. 

    If you had a suspected allergic reaction which was not anaphylaxis after a COVID-19 vaccine, or to one of its ingredients, you may still be able to have the second dose of the vaccine, but in some cases precautions are needed such as a longer period of observation after vaccination or referral for allergy testing

    You can find out more about the ingredients in COVID-19 vaccines in the Consumer Medicine Information, which is available on the TGA website.

  • Can I have a COVID-19 vaccine if I have a history of Guillain-Barre Syndrome?

    Yes, if you have a past history of GBS, you can have a COVID-19 vaccine. There have been cases of GBS following vaccination in Australia and overseas. The European Medicines Agency (EMA), the US Advisory Committee on Immunisation Practices (ACIP) and the World Health Organisation Global Advisory Committee on Vaccine Safety (GACVS) have reviewed cases of GBS following COVID-19 vaccination. At this stage, it is not yet clear whether the reports of GBS are linked to vaccination.

    GACVS recommended that individuals receiving the AstraZeneca or Janssen vaccines should seek immediate medical attention if they develop signs and symptoms of GBS. 

    Symptoms may include: 

    • difficulty in walking
    • difficulty with facial movements
    • double vision or inability to move eyes
    • difficulty controlling bladder or bowel functions.
  • What is Bell’s palsy? Can COVID-19 vaccines lead to Bell’s palsy?

    Bell’s palsy causes paralysis (weakness) of one side of the face. The exact cause is not known, but it is thought to often be triggered by a recent viral illness. It is treatable, and most cases resolve fully.

    The evidence to date does not support an association between COVID-19 vaccines and Bell’s palsy. However, cases of Bell’s palsy have been reported after COVID-19 vaccines. There were four cases of Bell’s palsy in the group of >18,000 participants who received the Pfizer vaccine in the phase 3 clinical trial, and there were no cases in the group who received the placebo. Cases of Bell’s palsy have also been reported after COVID-19 vaccines in several countries. 

    It is not yet known whether these reported cases are coincidental, because they have not been reported at a higher rate than what would be expected in the general population. 

  • Can I have a COVID-19 vaccine if I have a past history of Bell’s palsy?

    Yes, if you have a past history of Bell’s palsy, you are recommended to have a COVID-19 vaccine. 

    The evidence to date does not suggest that COVID-19 vaccines can trigger Bell’s palsy. 

  • What is myocarditis and pericarditis? Can the Pfizer vaccine or the Moderna vaccine lead to myocarditis and pericarditis?

    Myocarditis is inflammation of the heart muscle. Pericarditis is inflammation of the outer lining of the heart. Myopericarditis is where these two conditions occur together.

    A risk of myocarditis and pericarditis has been seen in people who have had mRNA vaccines (including the Pfizer vaccine and the Moderna vaccine) overseas, including in the USAIsrael and the UK. Cases have been reported more commonly in males aged <30 years, and mostly after the second dose. The WHO GACVS has reported that some countries have reported higher rates of myocarditis following the Moderna vaccine, compared with the Pfizer vaccine, but further studies are being done to confirm this. Most cases have been mild and these countries continue to recommend that the benefits of mRNA vaccine strongly outweigh the risk of myocarditis or pericarditis, as does the WHO GACVS.

    Cases of myocarditis and pericarditis after vaccination have also been reported in Australia. The TGA is monitoring these cases. Both these conditions occur relatively commonly in the general population, and not all cases that are reported after vaccination will be caused by the vaccine (i.e. some may occur coincidentally). 

    Myocarditis and pericarditis cases have also been reported after the AstraZeneca vaccine in the UK; however, these have not been reported more commonly than would be expected in the general population. 

    The Australian Technical Advisory Group on Immunisation (ATAGI) has provided guidance on myocarditis and pericarditis after mRNA vaccines. ATAGI emphasises that the benefits of vaccination outweigh the rare risk of myocarditis and pericarditis. Both mRNA vaccines continue to be recommended for all people aged 16 years and older who do not have any contraindications to the vaccines. 

    Symptoms of myocarditis and pericarditis, linked to mRNA vaccination, appear within 1-5 days of vaccination and are typically mild and recover quickly. Possible symptoms of myocarditis or pericarditis include: 

    • chest pain, pressure or discomfort 
    • palpitations (irregular heartbeat, skipped beats or ‘fluttering’). 
    • syncope (fainting) 
    • shortness of breath 
    • pain with breathing. 

    If you experience any of these symptoms, you should seek prompt medical attention. It is important to note that there could be other causes for these symptoms that are not related to the vaccine.
     

  • Can I have the Pfizer or Moderna vaccine if I have a cardiac condition?

    The Pfizer vaccine continues to be one of the recommended vaccines to prevent COVID-19 in people with a history of most chronic cardiovascular conditions, including:

    • myocarditis, pericarditis or endocarditis in the past (i.e. more than 3 months before vaccination)
    • coronary artery disease
    • myocardial infarction (a ‘heart attack’)
    • stable heart failure
    • arrhythmias (rhythm disturbances of the heart)
    • prior rheumatic heart disease (RHD). This includes people who have had rheumatic fever in the past and are taking antibiotics to prevent recurrence.
    • Kawasaki disease
    • congenital heart disease
    • cardiomyopathy
    • heart transplant
    • people with implantable cardiac devices.

    No specific precautions are recommended for people in these groups. There are no current data suggesting that their risk of developing myocarditis or pericarditis after vaccination is any higher than that for the general population.

    If you have or have had any of the following heart conditions, you can still have the Pfizer or Moderna vaccine, but you should talk to your doctor first to discuss the best timing of vaccination, and whether any extra precautions are needed:

    • recent (i.e. within the last 3 months) or current myocarditis or pericarditis  
    • acute rheumatic fever or acute rheumatic heart disease
    • severe heart failure. 
       

    If myocarditis or pericarditis has developed and has been attributed to the first dose of an mRNA vaccine, defer further doses of an mRNA vaccine (which would include both Pfizer and Moderna vaccines), and discuss options regarding future doses with your doctor.   

    Further details are available on the COVID-19 vaccination – ATAGI clinical guidance on COVID-19 vaccine in Australia in 2021 and in the Guidance on Myocarditis and Pericarditis after mRNA COVID-19 vaccines

  • If I have had myocarditis or pericarditis after dose 1, can I have dose 2?

    If you have symptoms potentially consistent with myocarditis and/or pericarditis after an mRNA COVID-19 vaccine, you should be referred to a cardiologist for further assessment and management, including to investigate possible causes of symptoms other than vaccination, and for follow-up.

    If you have a confirmed diagnosis of myocarditis linked to an mRNA COVID-19 vaccine, ATAGI currently recommends discussing with a specialist immunisation service and/or cardiologist about subsequent administration of COVID-19 vaccine dose.

    The ATAGI guidance on myocarditis and pericarditis after mRNA COVID-19 vaccines (last updated on 28 October 2021) provides information on next steps for those who experience pericarditis after an mRNA vaccines. 

    For further advice on mixed schedules, refer to ATAGI clinical advice on use of a different COVID-19 vaccine as the second dose in special circumstances.

  • What is capillary leak syndrome? Can COVID-19 vaccine lead to capillary leak syndrome?

    Capillary leak syndrome is an extremely rare but severe relapsing-remitting condition where fluid from small blood vessels (capillaries) leaks into surrounding tissue.

    Cases of capillary leak syndrome after the AstraZeneca vaccine have been reported overseas. The TGA has received a report of one case of a patient who died from multi-organ failure but had signs of capillary leakage. It is not clear whether this was linked to the AstraZeneca vaccine as other causes could not be ruled out.

    The Pharmacovigilance Risk Assessment Committee (PRAC) in Europe is reviewing reports of capillary leak syndrome. At this stage, it is not yet clear whether the reports of capillary leak syndrome are linked to vaccination. 

  • Can I have a COVID-19 vaccine if I have a past history of capillary leak syndrome?

    A past history of the capillary leak syndrome is a contraindication to  the AstraZeneca vaccine. This means if you have had capillary leak syndrome in the past, you should have an alternative vaccine. 

  • What is immune thrombocytopenia (ITP) and can the COVID-19 vaccines lead to ITP?

    Immune thrombocytopenia (ITP) is a rare bleeding disorder. It can occur after the immune system is activated, for example by a viral infection or vaccination. ITP has been reported with other vaccines such as for hepatitis B, measles, mumps, rubella and influenza. Up to a third of people with ITP will have no symptoms at all or have only minor bruising. However, about 5% develop severe bleeding. 

    The risk of ITP associated with the AstraZeneca vaccine is still being investigated and characterised. Early findings from a recent Scottish study estimate the risk of ITP to be about 1 case per 100,000 AstraZeneca doses. This study did not find clear evidence of any association between the Pfizer vaccine and ITP.

    As at 31 October 2021, the Therapeutic Goods Administration (TGA) had received 87 reports of suspected ITP following COVID-19 vaccination. The TGA is closely monitoring ITP after one case of a 61-year-old woman from Western Australia who developed severe ITP after receiving the AstraZeneca vaccine and unfortunately died. 

    The TGA encourages people to seek medical attention if they experience signs and symptoms that could suggest ITP, such as unusual skin bruising or clusters of small red or purple spots that do not lose their colour when pressed. Unusual bleeding is another sign, for example bleeding from the nose or mouth that is hard to stop, or blood in the urine or stools.

Questions about vaccine development

  • What types of vaccines have researchers developed?

    Researchers have used and are using a variety of methods to develop COVID-19 vaccines, some of which are well established and some newer.

    Established technologies use either the whole virus or parts of the virus (usually proteins) to train the immune system to recognise it. These technologies include:

    • inactivated vaccines, where the whole virus is inactivated with chemicals or heat so that it cannot replicate
    • subunit vaccines, where only a component of the virus is used, such as a protein
    • live attenuated vaccines, which contain a weakened version of the virus. There are currently no live attenuated COVID-19 vaccines in clinical trials.
       

    Newer technologies used in the development of COVID-19 vaccines use the genetic code for a component of the SARS-CoV-2 virus, usually the spike protein or the part of it called the receptor binding domain. After vaccination, host cells take up the genetic code and manufacture that protein, which then triggers an immune response. These technologies include:

    • DNA and mRNA vaccines, which are molecules that contain genetic information (genes). These technologies have been under development for decades. 
    • viral vector vaccines in which a chemically weakened harmless virus like a common cold adenovirus (the vector) is used to carry the genetic code for the spike protein from SARS-CoV-2. There are currently two licensed viral vector vaccines for humans, both for the Ebola virus. Viral vectors are also used in licensed gene therapy products.
  • How have COVID-19 vaccines been tested?

    Before a vaccine is registered for use, it is tested extensively during development and then in thousands of people. Testing first begins with laboratory research, then animal studies and finally human clinical trials.

    Clinical trials involve testing the vaccine in volunteers, and are conducted in phases:

    • Phase 1 clinical trials usually include a few dozen healthy adult volunteers and focus primarily on assessing safety, and also on demonstrating that the vaccine induces an immune response
    • Phase 2 clinical trials have hundreds of volunteers, and can include groups for whom the new vaccine is intended, for example, older adults, children or people with pre-existing medical conditions. These trials aim to show the vaccine induces an immune response and confirm that it is safe with acceptable side effects.
    • Phase 3 clinical trials include many thousands of participants and aim to show that a vaccine has efficacy (i.e. it is effective) in preventing people from getting the disease – in this case COVID-19. Phase 3 trials also thoroughly assess the vaccine for safety and side effects. In a phase 3 trial, researchers usually compare vaccinated people with people who received a placebo (like a salt water injection). They compare the rate of disease, disease severity and reported side effects between the two groups.
       

    For COVID-19 vaccines, some of these phases have been combined. For example, in phase 1/2 trials, results are analysed after the first few dozen volunteers are studied, then the trial proceeds in hundreds more. Also, some phase 3 studies have started once preliminary data from phase 1/2 trials are available. Having these ‘overlapping’ time frames has helped develop COVID-19 vaccines quickly and help make them available earlier to save lives.

  • Why are clinical trials sometimes paused and restarted?
    • COVID-19 vaccine trials, in the same way as other vaccine clinical trials, are supervised by independent Data and Safety Monitoring Boards (also known as DSMBs). DSMBs can advise to pause or stop a trial if there are any safety events, such as a participant experiencing a severe illness or event that needs time to investigate more fully. This standard procedure is one of the important ‘checks and balances’ in clinical trials. Pausing a trial allows researchers to investigate the event and see if it may have been a side effect related to the vaccine or if it is coincidental. Since clinical trials usually include tens of thousands of participants and continue for many months, it is inevitable that some participants will experience unrelated illnesses during the trial.

    If researchers are concerned that the vaccine is causing unacceptable side effects, they can stop the trial. This has not yet happened for any COVID-19 vaccine trials.  

  • What is the process for getting a COVID-19 vaccine approved in Australia?

    The Therapeutic Goods Administration (TGA), part of the Australian Government Department of Health, is the organisation responsible for approving medicines and vaccines for use in Australia. Approved products are listed on the Australian Register of Therapeutic Goods. The TGA receives advice from an independent panel of experts on the Advisory Committee on Vaccines. The approval process involves a rigorous assessment of vaccine effectiveness and safety. Given the urgency of the pandemic, the TGA is prioritising COVID-19 vaccines via a faster pathway which involves the following steps:

    Provisional determination

    Being granted provisional determination means that a vaccine developer is eligible to proceed to apply for provisional registration from the TGA. It does not mean that provisional approval has been granted, but that the vaccine can be assessed by the TGA using the provisional registration pathway.

    As of 24 June 2021, the TGA had granted provisional determination to five companies for their COVID-19 vaccines:

    • AstraZeneca Pty Ltd, for the University of Oxford vaccine
    • Pfizer Australia Pty Ltd, for the Pfizer/BioNTech vaccine  
    • Janssen Cilag Pty Ltd, for the Janssen vaccine
    • Biocelect Pty Ltd (on behalf of Novavax Inc.), for the Novavax vaccine 
    • Moderna Australia Pty Ltd, for the Moderna (Spikevax) vaccine

    As at June 2021, the TGA has not granted provisional determination to any other company.

    Provisional approval

    The provisional approval pathway is a process that allows for temporary registration of promising new medicines and vaccines where the need for early access outweighs any potential risks. The decision to grant provisional registration is based on a number of factors, including:

    • the safety, quality and effectiveness of the vaccine has been satisfactorily established for its intended use
    • the sponsor’s plan to submit comprehensive clinical data before the provisional registration ends.

    After provisional approval, the TGA will continue to closely monitor any new data about the vaccine as it becomes available. Similar processes are used by regulatory authorities in other countries, such as the United States Food and Drug Authority and the European Medicines Agency.

    As of 9 August 2021, the TGA has granted provisional approval to four companies for their COVID-19 vaccines:

    • Pfizer Australia Pty Ltd, for Comirnaty
    • AstraZeneca Pty Ltd, for COVID-19 Vaccine AstraZeneca 
    • Janssen Cilag Pty Ltd, for the Janssen vaccine
    • Moderna Australia Pty Ltd, for the Moderna (Spikevax) vaccine
       
  • UPDATED - Why are COVID-19 vaccines being developed so quickly?

    As of 19 November 2021, more than 5.1 million people have died from COVID-19 globally, and more are dying each day. In Australia, 1,942 people have died and approximately 198,445 people have been infected. Hundreds of millions of people are suffering from the ongoing social and economic devastation caused by the pandemic. The urgency of this crisis means that all available resources and efforts are have been directed towards finding effective vaccines.

    Developing and licensing a vaccine has in the past taken a decade or longer, but some COVID-19 vaccines have been registered and used within 12 months of the virus being discovered..

    Some of the reasons behind this rapid progress include:

    • Unprecedented funding and collaboration between vaccine developers and governments around the world. Financial risks have been taken, such as building manufacturing facilities before a vaccine is even available.
    • Technology has evolved to make vaccine development faster than in the past. Previously, viral vaccines could only be developed after growing the virus in a lab, which takes time. Newer technologies build vaccines using the genetic code for the virus, so researchers around the world were able to start their work as soon as the genome for the virus was released in January 2020.
       

    Clinical trials progress more quickly if a disease is widespread, as is the case with COVID-19 in many countries, as a significant difference between the unvaccinated and vaccinated groups can be detected sooner than for a rare disease.

Visit our COVID-19 vaccination program in Australia page to find the latest information and resources on the COVID-19 vaccination program, ATAGI statements and more.
 
Visit our COVID-19 vaccine development landscape page to understand the current state of development of COVID-19 vaccines and clinical trials.