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 3 May 2021).

Questions about vaccination program

  • How many people in Australia have been vaccinated? 

    As of 3 May 2021, 2.26 million vaccine doses have been administered in Australia. Of those:

    • over 1.2 million doses were administered in the primary care setting (GP sites, GPRC sites, ACCHS)
    • over 200,000 doses were administered in aged and disability facilities
    • over 800,000 doses were administered in state and territory clinics.

    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), an mRNA vaccine. Comirnaty is registered for use in people aged 16 years and older, and is currently the preferred COVID-19 vaccine brand for use in people under 50 years of age. The Australian Government has secured 40 million doses of this vaccine.
    • COVID-19 Vaccine AstraZeneca, a viral vector vaccine. The AstraZeneca vaccine is registered for use in people aged 18 years and older. The Australian Government has secured 53.8 million doses of this vaccine; 3.8 million to be imported and 50 million to be manufactured in Australia.
       

    The Australian Government has a third 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.

    The Therapeutic Goods Administration had granted provisional determination for review of Janssen Cilag Pty Ltd, another viral vector vaccine. However, this vaccine is not yet registered and review of the vaccine by the TGA has currently been paused due to an investigation by US and European authorities of reports of the blood clotting disorder called thrombosis thrombocytopenia syndrome (TTS) following vaccination.

  • Who can get a COVID-19 vaccine and how is the priority decided?

    It will take time for enough vaccine doses to be manufactured so that the entire population in Australia can be vaccinated. There are significant global constraints that impact COVID-19 manufacturing and supply. Initially, the covid-19 vaccine will be offered using a 'priority framework' that outlines how to allocate the initially limited available doses. 

    The Australian Government, informed by ATAGI and other medical expert groups, has published detailed information outlining priority populations on the basis of a number of factors, including where COVID-19 infections are occurring, the risk of infection and severe disease, and the characteristics of the available vaccines. 

    Similar priority lists have been developed around the world, including by the World Health Organization, the United Kingdom Joint Committee on Vaccination and Immunisation and the United States Centers for Disease Control and Prevention. 

    As quarantine and border workers, frontline health care workers and aged care and disability care staff workers are at high risk of contracting COVID-19 and also may spread the virus to vulnerable patients and the elderly, they have been identified as groups to be offered the vaccine first, along with aged care and disability residents under phase 1A. 

    Children are not an initial priority group for COVID-19 vaccination because of lesser disease severity in children than in older people.

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

    COVID-19 vaccines are free for everyone in Australia, as per the Australian COVID-19 Vaccination Policy

    Some people will be able to access the vaccine through their workplace (e.g. healthcare workers, residential aged care facility workers). Others will be able to access the vaccine through general practices (that meet specific requirements), GP respiratory clinics, Aboriginal Controlled Community Health Services, and state-run vaccination clinics.

    To find out if you are eligible to be vaccinated, check the COVID-19 Vaccine Eligibility Tracker. If you are eligible to be vaccinated now, you will be able to view vaccination clinics and book an appointment. If you are not yet eligible, you can register your interest so you will be notified when you are able to book.

     

     

     

     

  • Is the COVID-19 vaccine mandatory?

    The Australian Government has stated that COVID-19 vaccination “is not mandatory and individuals may choose not to vaccinate”. If people choose not to have a COVID-19 vaccine, this will not affect their family’s eligibility for Family Tax Benefit Part A or childcare fee assistance which only includes National Immunisation Program vaccines for those aged <20 years.

    It is possible that in future, vaccination against COVID-19 may become a requirement for travel to certain destinations or for people working in certain high-risk workplaces. If this becomes the case, it is anticipated there will be exemptions in place for people who are unable to be vaccinated.

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

    Herd immunity occurs when enough people are vaccinated to prevent the SARS-CoV-2 virus from easily spreading from person to person. Eventually, most of the population may be able to be protected from a particular disease if the vaccine is sufficiently protective and enough people in the population are vaccinated. 

    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. 

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

    As of 2 May 2021, over 1.16 billion doses of a COVID-19 vaccine have been given to people worldwide, the most common vaccines used to date are:

    • The AstraZeneca viral vector vaccine (139 countries)
    • Comirnaty (Pfizer), an mRNA vaccine (90 countries)
    • Moderna’s mRNA vaccine (42 countries)
    • Beijing/Sinopharm’s inactivated vaccine (35 countries)
    • Gamaleya’s viral vector vaccine (31 countries)
    • Sinovac’s inactivated vaccine (24 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.

  • Do we still need other COVID-19 prevention measures like social distancing and lockdowns even though a COVID-19 vaccine is available?

    Australia still needs to keep the flexible and extensive strategies already in place to control COVID-19 during the rollout of the vaccine program. Once the vaccine is able to be given to a high proportion of people, it is anticipated that we will be able to reduce some of these control measures. 
    This is likely to be a step-wise process, done cautiously, and will rely on as many people as possible being willing to have the vaccine.

  • Why are multi-dose vials being used to store COVID-19 vaccines?

    Multi-dose vials contain more than one dose of a vaccine in a single glass vial. They usually include 5–20 doses per vial. Each dose is then carefully extracted and given via individual syringes for injection. Use of multi-dose vials is the most efficient way to distribute a new vaccine to the maximum number of people and is being used world-wide for all COVID-19 vaccines. 

    Packaging vaccine doses multi-dose vials is safe and is supported by numerous quality controls and good handling practices. 

    Multi-dose vials are routinely used in Australia for the tuberculosis (BCG) vaccine and were used for the 2009 pandemic influenza vaccine. Immunisation providers are trained in, and follow guidelines specifically on, the use of multi-dose vials.

  • How are COVID-19 vaccination encounters recorded?

    All vaccines given must be recorded on the Australian Immunisation Register (AIR). All immunisation providers must submit this information to AIR following the administration of the vaccine.  

    Individuals can view their vaccination history and download a statement using a Medicare online account accessed through myGov or the Express Plus Medicare mobile app. For those that can’t use Medicare online, vaccination providers can print the immunisation history statement or you can call AIR on 1800 653 809. 
     

Questions about getting vaccinated

  • 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 3 May 2021, it has caused over 3.1 million deaths worldwide, with more than 152 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 amount of people are vaccinated, this will decrease the spread of COVID-19 in our community. 

  • Can I choose which COVID-19 vaccine I get?

    Right now, people can’t choose which vaccine they are offered. However, the Australian Government is currently reviewing the vaccine rollout in light of a safety concern associated with the AstraZeneca vaccine (see Vaccine Safety section). Daily updates about the vaccine rollout are available at the Australian Government website.

    People aged 16-50 years are currently preferred to be offered Comirnaty (the Pfizer vaccine). However, people in this younger age group can still choose to have the AstraZeneca COVID-19 vaccine now if they consider the benefits of vaccination outweigh the risk for them.

    It has not yet been determined what changes will need to be made to the vaccine rollout to allow increased access to doses of Comirnaty for people under 50 years of age.

    This section will be updated as further information becomes available.

     

  • What is Comirnaty 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 COVID-19 Vaccine AstraZeneca and how does it work?

    COVID-19 Vaccine AstraZeneca 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, COVID-19 Vaccine AstraZeneca does not behave like a ‘live vaccine’.

  • 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 COVID-19 Vaccine AstraZeneca 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.

    The Comirnaty (Pfizer), requires two doses, recommended to be given 3 weeks apart.

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

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

    If the second dose of either Comirnaty or COVID-19 Vaccine AstraZeneca is overdue (i.e. past the recommended interval) the second dose 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.

    Additional or booster doses beyond the two-dose course are not currently recommended. 

    The need for any additional doses will be reviewed over time.
     

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

    Routine administration of a COVID-19 vaccine on the same day as another vaccine, including an influenza vaccine, is not recommended. The preferred minimum interval between receipt of COVID-19 vaccine and any other vaccine is 14 days.

    Other, non-COVID-19 vaccines can be given either side of a COVID-19 vaccine dose if the interval is followed. It doesn’t matter which vaccine you receive first. Depending on vaccine availability, take whichever vaccine you have access to first.

    The COVID-19 vaccine program is not planned to impact on the 2021 influenza vaccine program. The influenza vaccine roll out is planned to continue as  usual.

    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.

  • How effective are COVID-19 vaccines?

    On the basis of information from clinical trials, Comirnaty (developed by Pfizer/BioNTech) is about 95% effective at preventing people from getting sick with COVID-19 and COVID-19 Vaccine AstraZeneca is at least 62–70% effective at preventing people from getting sick with COVID-19. Higher efficacy estimates for COVID-19 Vaccine AstraZeneca have been reported in some clinical trials.
    Real world studies (also called observational or post-market vaccine effectiveness studies) are also showing strong protection from both vaccines.

    Preliminary results from a study in Scotland, of both Comirnaty and COVID-19 Vaccine AstraZeneca, suggest that both vaccines are very effective at preventing serious illness and hospitalisation from COVID-19. People given Comirnaty were around 85% less likely to need to go to hospital if they developed COVID-19. This figure was around 94% for those given COVID-19 Vaccine AstraZeneca.

    Data from Public Health England have also shown that both Comirnaty and COVID-19 Vaccine AstraZeneca are highly effective in reducing COVID-19 in people aged ≥70 years, and in reducing serious illness requiring hospitalisation. People were around 57–61% less likely to get sick from COVID-19 after a single dose of a Comirnaty and around 60–73% protected after a single dose of COVID-19 Vaccine AstraZeneca.

    More information about the effectiveness of both vaccines will become available over time.

    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 and how effectively they will decrease transmission (the spread of disease between people) – refer to What is herd immunity and how does it relate to the COVID-19 vaccination program?

  • 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. This may mean that the effectiveness of the current vaccines against this particular strain could be affected. This information is still emerging and is being closely monitored. 

    In the same way that the influenza vaccine changes each season, the technology used to create the COVID-19 vaccines may be able to be adapted to changes in variants. 

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

    Pfizer has announced that Comrinaty provides immunity for at least 6 months. Comrinaty was found to be 91.3% effective against symptomatic COVID-19 up to 6 months after the second dose.

    As clinical trials are ongoing, and people have only started to be vaccinated in some other countries since around December 2020, we do not yet know how long immunity from COVID-19 vaccines will last.  . 

    We will gather more information about the duration of protection over the coming months, including for the AstraZeneca vaccine. 

  • Can different COVID-19 vaccines be used interchangeably?

    It is generally not recommended to use COVID-19 vaccines interchangeably, since we do not yet know whether this is effective.

    You should ideally have two doses of the same COVID-19 vaccine to complete your course.

    However, this advice may change over time as more data emerges. For example, a clinical trial of vaccination with alternating doses of Pfizer and AstraZeneca vaccines is being conducted in the United Kingdom.

  • Should I wait for a better COVID-19 vaccine?

    The COVID-19 vaccines we will have in Australia are safe and effective, and it is strongly recommended to get vaccinated as soon as you are offered a vaccine.

    Some changes to the program are being made which will impact who is offered which vaccine, where and when. Be sure to check the Australian Government COVID-19 vaccine program website for any updates.

    Having a COVID-19 vaccine now offers you and others protection against the disease and is the fastest way to reducing our need for strict COVID-19 related measures.

    Having one course of COVID-19 vaccination now will not mean you will not be eligible to have another COVID-19 vaccine in future – it is possible that additional or booster doses of vaccine are needed in the future. More data will come on this over time.

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

    COVID-19 vaccines are available to adults, even people with a history of SARS-CoV-2 infection. 

    The vaccine clinical trials included some previously infected people (who 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 weren’t previously infected.

    If you have previously been diagnosed with COVID-19, you should talk to your healthcare provider about the best time to have a COVID-19 vaccination. You may be advised to wait until around 6 months after you have recovered from COVID-19 to have your vaccine. 

  • What happens if I get COVID-19 between the first and second dose of a COVID-19 vaccine?

    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. 

    Some people who have just had one dose of the vaccine may develop COVID-19 disease. If you are infected and have only had one dose of vaccine, you will still be able to have the second dose of COVID-19 vaccine, but you may be advised to delay the second dose for around 6 months after you have recovered from COVID-19.

    Some people may also develop COVID-19 disease after two doses; however, it is expected symptoms will not be severe. Further evidence is awaited that will provide more insight on this. 

  • 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.

  • Can children have a COVID-19 vaccine?

    Children under 16 years of age cannot have Comirnaty, the Pfizer COVID-19 vaccine. Children and adolescents under 18 years of age cannot have the AstraZeneca COVID-19 vaccine. 

    This is because we don’t have any clinical trial results yet to confirm that the vaccines are effective and safe in these age groups. Clinical trials in children are planned or underway, and in the future children may be able to receive both of these vaccines.

  • From what age can a person with medical condition get a COVID-19 vaccine?

    People with specific underlying medical conditions will be eligible for access to COVID-19 vaccines once Phase 1b of the COVID-19 vaccine program commences. 

    People with chronic medical conditions can receive either Comirnaty (Pfizer) or COVID-19 Vaccine AstraZeneca. There is no preference for one vaccine over another in people with medical conditions and such people can access whichever vaccine is made available to them at a COVID-19 immunisation site.

    At the current time, the Comirnaty (Pfizer) vaccine is registered from ≥16 years of age and the COVID-19 Vaccine AstraZeneca is registered from ≥18 years. Thus, a 16- or 17-year old with a medical condition is eligible for Comirnaty for protection, and services should seek to ensure this can occur.

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

    COVID-19 vaccines are not routinely recommended in pregnancy, because pregnant women have not been included in clinical trials.

    However, some pregnant women may still choose to be vaccinated after considering the benefits and risks of vaccination. 
    In particular, a pregnant woman may wish be vaccinated if she has risk factors for severe illness from COVID-19 or if she is at high risk of exposure to COVID-19, for example, because of her occupation.

    Comirnaty is preferred over COVID-19 AstraZeneca in people under the age of 50 years, and in pregnant women. This is because a very rare new side effect called thrombosis thrombocytopenia syndrome (TTS), associated with COVID-19 Vaccine AstraZeneca. TTS involves blood clotting and low blood platelet count. Comirnaty (Pfizer) is not associated with a risk of TTS. 

    Women who are breastfeeding can have a COVID-19 vaccine, and they don’t need to stop breastfeeding after vaccination. There are no theoretical safety concerns about the currently available COVID-19 vaccines for breastfeeding women or their babies. 

    Women who are planning pregnancy can have a COVID-19 vaccine, and they don’t need to avoid becoming pregnant after vaccination. 

    Either of the COVID-19 vaccines approved in Australia – Comirnaty (Pfizer) or COVID-19 Vaccine AstraZeneca – is suitable for women who are breastfeeding or planning pregnancy. 

    For more information it is advised that women talk to their healthcare provider and refer to the COVID-19 vaccination decision guide for women who are pregnant, breastfeeding or planning pregnancy.

  • 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 either of the COVID-19 vaccines currently approved in Australia – Comirnaty (Pfizer) or COVID-19 Vaccine AstraZeneca. 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.

    Both 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. 

    Comirnaty (Pfizer) is not a live vaccine. COVID-19 Vaccine AstraZeneca 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. 

  • 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 hayfever. 

    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 Comirnaty, or polysorbate 80, an ingredient in COVID-19 Vaccine AstraZeneca) 
    • people who have a mast cell activation disorder.
  • 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 history of Guillain Barre Syndrome (GBS), you can have a COVID-19 vaccine. There is no evidence that either Comirnaty or COVID-19 Vaccine AstraZeneca is associated with GBS.

    Countries that have used these vaccines have not reported any association between vaccination and GBS.

    There were no cases of GBS reported after vaccination in the clinical trials for these vaccines. 
     

  • Does the AstraZeneca vaccine cause blood clots?

    COVID-19 Vaccine AstraZeneca 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 platelet levels (thrombocytopenia), and occurs around 4-28 days after vaccination. It is currently estimated to affect around 6 people per million doses. To date, almost all reported cases were after the first dose of the vaccine. 

    Comirnaty (Pfizer) is not associated with a risk of TTS. 

    Not all clots that occur after having COVID-19 Vaccine AstraZeneca will be due to TTS. 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 50 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 COVID-19 Vaccine AstraZeneca, since women make up a large proportion of frontline healthcare workers and who have been prioritised for vaccination.

     

  • Why is Comirnaty (Pfizer COVID-19 vaccine) now preferred for people under 50?

    Comirnaty is recommended as the preferred vaccine over AstraZeneca vaccine for people under 50 years of age based on 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.

    On 23 April 2021, ATAGI updated the estimated rate of TTS in people under 50 years of age in Australia to be approximately 20-40 cases per 1 million people vaccinated. By comparison, younger people have a much lower risk of severe illness, hospitalisation or death from COVID-19 than older adults. 

    For adults over 50 years of age, the benefits of vaccination with COVID-19 AstraZeneca 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.

    While Australia has no ongoing community transmission of COVID-19 at present, the virus could spread in the community at any time. If community transmission increases significantly, then the benefits of vaccination with AstraZeneca COVID-19 vaccine may be greater than the risk for all people, including people under 50 years of age.

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

    People under 50 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 the most widely available vaccine in Australia at the current time and is recommended for people age 50 years and older.

    Comirnaty (Pfizer vaccine) is preferred for adults under the age of 50 years, with a focus on those in phases 1a and 1b at this time. 

  • 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
    • vomiting, and may be worse when lying down
    • 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 COVID-19 Vaccine AstraZeneca. 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 4-28 days after vaccination with COVID-19 Vaccine AstraZeneca. 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, about 80% of people who had TTS survived, and 19% 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?

    Yes, almost all people who have a history of blood clots can have either AstraZeneca or Comirnaty COVID-19 vaccines, according to their age. 

    Comirnaty is not associated with a risk of thrombosis with thrombocytopenia syndrome (TTS). It is the preferred vaccine for people under 50 years of age. 

    Comirnaty is also preferred for people with a past history of cerebral venous sinus thrombosis (CVST) or heparin-induced thrombocytopenia (HIT). This is because both of these conditions share features with TTS. These conditions theoretically may be associated with an increased risk of TTS, although there is no evidence yet to suggest that this is the case.

    People with a history of other types of blood clots who are over 50 years of age can still have the AstraZeneca vaccine, because the benefits of vaccination are greater for this age group, and the risk of TTS remains very low.

    People under 50 years of age are recommended to receive Comirnaty in preference to AstraZeneca vaccine.

    Anyone with a history of blood clotting disorders who is under 50 years of age and is considering AstraZeneca vaccine should discuss the benefits and risks of vaccination with their healthcare provider.

    There is no evidence that any other type of clotting disorder increases the risk of TTS. However, to date in the world only around 300-400 cases of the condition have been described (among hundreds of millions of people given the AstraZeneca vaccine) and it has not been possible to understand if people with other clotting disorders have a higher risk of TTS after vaccination. 

    For further information, refer to Weighing up the potential benefits against risk of harm from COVID-19 Vaccine AstraZeneca resource.

  • 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 (1, 2, 3) of patients who had TTS after AstraZeneca vaccine, and in both case series, no patient had a history of exposure to heparin. 

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

    As of 23 April 2021, thrombosis with thrombocytopenia syndrome (TTS) has predominantly been reported after a first dose of the AstraZeneca vaccine. It is not known what the risk of TTS may be after the second dose, but it appears lower.

    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 50 years of age.

    People who have had a blood clot associated with low platelet counts after their first dose of 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.
     

  • 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. 
     

Questions about vaccine safety

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

    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 coronavirus. 

    The vaccines used in Australia and elsewhere contain a genetic material that codes for the spike protein (eg, Pfizer 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 4-28 days after vaccination. Be sure to seek medical attention if you have any concerns (see also the question above 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
     

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

    Comirnaty (Pfizer) and AstraZeneca/University of Oxford COVID-19 vaccine do not contain any gelatine. 

    List of ingredients for Comirnaty (Pfizer)

    List of ingredients for ChAdOx1-S (AstraZeneca/University of Oxford) 

    Once other vaccines are approved for use in Australia, a list of ingredients will be available for those vaccines too.

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

    There are no cells from aborted tissue in any COVID-19 vaccine. During the development of the AstraZeneca vaccine, cells were used that were derived from a fetus aborted in the 1970s. The abortion was elective, and was not done for the purpose of research. Fetal cell lines were not used in the development or manufacturing of Comirnaty (the Pfizer vaccine), 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 Comirnaty (the Pfizer 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 Comirnaty (Pfizer) 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 Comirnaty (Pfizer) in the USA as of February 2021 was 4.7 cases per million people. 

  • Does COVID-19 Vaccine AstraZeneca contain a live virus?

    No. The COVID-19 Vaccine AstraZeneca 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). 

  • Are shortcuts being taken in vaccine safety assessment?

    No. Although COVID-19 vaccine trials have been set up much more quickly than would have previously been possible, this does not mean that safety assessment has been compromised.

    In fact most of the vaccines being developed have now included tens of thousands of people in their trials, totalling nearly one quarter of a million people being involved in trials altogether. This is actually providing a larger amount of data than for many other vaccines routinely used (refer also to How are COVID-19 vaccines being tested?)

    Each country has its own processes for assessing and monitoring the safety of vaccines. In Australia, any COVID-19 vaccine must meet the same high standards of the TGA as any other vaccine. Vaccine safety remains the TGA’s top priority. COVID-19 vaccines will be prioritised, and more resources will be allocated to their assessment.

    Safety monitoring allows us to pick up rare unexpected side effects and adjust vaccine program recommendations and information, as has occurred recently in Australia. 

  • 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.

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. However, there have not yet been any DNA or mRNA vaccines registered for use in humans.
    • 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 29 January 2021, the TGA had granted provisional determination to four 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 

    As at April 2021, 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 4 March 2021, the TGA has granted provisional approval to two companies for their COVID-19 vaccines:

    • Pfizer Australia Pty Ltd, for Comirnaty
    • AstraZeneca Pty Ltd, for COVID-19 Vaccine AstraZeneca 
  • Why are COVID-19 vaccines being developed so quickly?

    As of 3 May 2021, more than 3.1 million people have died from COVID-19, and more are dying each day. In Australia, 910 people have died and approximately 30,000 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.

  • Why was the University of Queensland COVID-19 vaccine abandoned?

    In a phase 1 trial this vaccine was found to trigger an immune response that may interfere with certain HIV diagnostic tests. The vaccine was based on the coronavirus spike protein. It also contained a protein fragment from the HIV virus, used to stabilise the spike protein. This protein fragment is harmless and cannot cause HIV or AIDS, but it can be recognised by the immune system, resulting in the production of antibodies against it.

    These antibodies were found to cause “false positive” results on HIV screening tests. This means the HIV screening test returned positive for participants who did not have HIV. This could cause confusion if people who received this vaccine needed to be screened for HIV at a later date. For this reason, the vaccine will not progress to phase 2/3 trials.

    It is common for some vaccines to fail during the development process, and this is partly why the Australian government secured advanced purchasing agreements with multiple vaccine developers.

Visit our COVID-19 vaccine development landscape page to understand the current state of development of COVID-19 vaccines and clinical trials.
 
Visit our COVID-19 vaccination program planning in Australia page to find the latest information about the COVID-19 vaccination program planning and vaccine rollout.