Respiratory syncytial virus (RSV): Frequently asked questions (FAQs)

Icon image: vaccine vial
Icon image: vaccine vial

NCIRS fact sheets, FAQs and other resources

Key points 

  • Respiratory syncytial virus (RSV) is a common virus that can cause a range of respiratory illnesses – from mild upper respiratory colds to severe lower respiratory conditions such as bronchiolitis (in infants) and pneumonia.
     
  • The RSV-associated hospitalisation rate is highest in infants under 6 months of age and generally declines sharply with age from early childhood. Hospitalisation rates then increase again in late adulthood.
     
  • The National RSV Mother & Infant Protection Program (RSV-MIPP), which commenced on 3 February 2025, is providing pregnant women in Australia with free access to the Abrysvo vaccine under the National Immunisation Program (NIP).
     
  • Additionally, the long-acting monoclonal antibody Beyfortus (nirsevimab) is available for free to eligible infants through state-and-territory-funded programs [PDF].
     
  • RSV immunisation with Arexvy is funded for Victorian residents aged 60 years and over in public and Aboriginal community-controlled aged care services.
     
  • RSV immunisation products are not currently funded for other recommended population groups.
     
  • ‘RSV immunisation products’ is the term used to encompass both RSV vaccines and RSV monoclonal antibody products.
     
  • A single dose of Abrysvo vaccine is recommended and NIP-funded for pregnant women of all ages from 28 weeks gestation to protect the infant via passive immunisation.
     
  • Another monoclonal antibody, Synagis (palivizumab) – which has been available in Australia for many years – is approved for use in infants and young children at risk of severe RSV disease.
     
  • A single dose of RSV vaccine (Arexvy or Abrysvo) is recommended for people aged 75 years and over, Aboriginal and Torres Strait Islander people aged 60 years and over, and adults aged 60 years and over with conditions that increase their risk of severe RSV disease.
     

Last updated: 1 August 2025

 

FAQs

General

Infants, young children and pregnant women

Older adults

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General

What is respiratory syncytial virus (RSV)?

RSV is a common virus that can infect people of all ages. It can cause a range of respiratory illnesses – from mild upper respiratory colds to severe lower respiratory conditions like bronchiolitis (in infants), bronchitis and pneumonia. 

Symptoms of RSV disease can include: 

  • runny nose
  • cough
  • fever
  • wheezing and difficulty breathing (including exacerbations of underlying lung disease such as asthma).
How is RSV disease spread?

RSV is spread through droplets from an infected person’s cough or sneeze. These droplets can: 

  • be inhaled by others
  • land on surfaces, where the virus can live for several hours.
Who is most at risk of severe RSV disease?

RSV can infect people at all ages; however, severe disease is most common in:

  • infants and young children under 12 months of age
  • young children aged under 24 months with underlying medical conditions
  • older adults
  • Aboriginal and Torres Strait Islander adults
  • adults with underlying medical conditions.
What is the RSV season and when does it occur?

RSV season is the time of year when most RSV cases occur. 

It varies by location and is primarily climate driven. In most temperate regions in Australia, seasonal outbreaks occur during autumn and winter, usually between April and September. The season tends to peak during June and July, often preceding the influenza season. 

In tropical regions, RSV seasonality can be less pronounced and may coincide with rainy seasons.

 

Infants, young children and pregnant women

How common is severe RSV disease in Australian infants and young children? 

Almost all children experience at least one RSV infection within the first two years of life. 

An NCIRS analysis [PDF] found that between 2016 and 2019, there were more than 115,000 hospitalisations with an RSV diagnosis in Australia, of which approximately 75% were of children aged less than 5 years. Most of these children were otherwise healthy. 

For infants aged less than 6 months, the annual RSV hospitalisation rate over the 2016–2019 period was approximately 3,100 per 100,000 population, with the highest rates in infants aged 0–2 months (approximately 7,200 per 100,000 population).

In Australia, RSV hospitalisations are more common in winter – however, they can occur year-round. Seasonal peaks are less noticeable in tropical regions such as the Northern Territory and North Queensland.

Which infants and young children are at greatest risk of requiring hospitalisation with RSV disease?

Infants and young children at greatest risk for serious RSV disease include: 

  • infants aged under 6 months – especially those aged under 3 months
  • young children aged 2 years and under with medical conditions such as chronic lung disease or congenital heart disease4
  • infants and young children aged 2 years and under who were born pre-term or with a low birth weight.

Aboriginal and Torres Strait Islander infants and young children aged 2 years and under are hospitalised with RSV at a rate around two times higher than the rest of the population.

What RSV immunisation products are available to protect infants and young children from severe RSV disease?

Two types of RSV monoclonal antibody products are available for administration to infants; one RSV vaccine is available for administration to pregnant women to protect the newborn infant. 

All of these options are designed to protect infants against severe RSV disease – either through passive immunisation or by injection of the infant with pre-made, RSV-specific monoclonal antibody. 

Passive immunisation occurs when a pregnant woman receives an RSV vaccine and their immune system makes antibodies that pass through the placenta to their baby. This provides the infant with protection from birth and during their first few months of life. 

There are currently no RSV vaccines available for infants for active immunisation in Australia or internationally. 

In Australia:

  • Abrysvo, an RSV vaccine for pregnant women for protection of their infants, was registered by the Therapeutic Goods Administration (TGA) in March 2024. It is now being funded for pregnant women in Australia under the National Immunisation Program (NIP).
  • Beyfortus (nirsevimab), a long-acting monoclonal antibody, was registered by the TGA in November 2023 for use as a single injection in infants. It is currently available through state- and territory-managed programs [PDF].
  • Synagis (palivizumab) has been registered for use in infants aged 24 months and under for many years; however, it needs to be given monthly during the RSV season and each dose provides only around one month of protection. 

For more information on the current status of RSV immunisation products in Australia, see Evaluation of and expected access to new RSV vaccines and long-acting monoclonal antibody (mAB) in Australia [PDF].

Which infants, young children and pregnant women are eligible to receive a free RSV immunisation product?

The Abrysvo vaccine is funded under the NIP for pregnant women only. 

State- and territory-funded programs are also providing free monoclonal antibody product (Beyfortus [nirsevimab]) for infants who are not protected through maternal vaccination and at-risk infants and young children. For more information, see State and territory nirsevimab (Beyfortus) infant program summary 2025 [PDF].

RSV immunisation products are not currently free for any other population groups but remain available via private purchase.

Do infants and pregnant women require a Medicare number to receive free RSV immunisation products under the NIP and state- and territory-funded programs?

Most pregnant women will require a Medicare number to receive a free dose of Abrysvo vaccine under the NIP. 

Pregnant women who are refugees or humanitarian entrants without a Medicare number are also eligible for a free dose of Abrysvo. 

Individuals without a Medicare number can also purchase a private prescription for Abrysvo.

Infants who are eligible to receive Beyfortus (nirsevimab) through state and territory programs do not need a Medicare number.

Which infants and young children are recommended to receive the long-acting RSV monoclonal antibody Beyfortus (nirsevimab)?

Beyfortus (nirsevimab) is recommended for the following infants (aged less than 8 months) and young children (aged less than 24 months):

  • infants born to mothers who did not receive a maternal RSV vaccine
  • infants born less than 2 weeks after their mother received a maternal RSV vaccine
  • infants born to mothers who were severely immunocompromised when they received a maternal RSV vaccine
  • infants who have undergone procedures (such as exchange transfusion, cardiopulmonary bypass or extracorporeal membrane oxygenation) that reduce the antibodies they will receive if their mother has a maternal RSV vaccine
  • infants and young children with certain risk conditions, regardless of whether their mother has had a maternal RSV vaccine.

Beyfortus (nirsevimab) is available (in all states and territories) through state- and territory-based programs to infants who are not protected through maternal vaccination and at-risk infants and young children. For more information on eligibility and availability, see State and territory nirsevimab (Beyfortus) infant program summary 2025 [PDF].

Clinical recommendations for Beyfortus (nirsevimab) and more information on its use can be found in the Australian Immunisation Handbook RSV chapter.

Which infants and young children are recommended to receive additional doses of Beyfortus (nirsevimab)? 

Young children aged 8 months to less than 24 months who are at high risk for severe RSV (see List. Conditions associated with increased risk of severe RSV disease in infants and young children) should receive Beyfortus (nirsevimab) before their second or third RSV season. This applies even if they received Beyfortus (nirsevimab) in their first or second season or if their mother received the Abrysvo RSV vaccine during pregnancy. 

A gap of at least 6 months is recommended between doses given in each season. The optimal timing of the second or third dose is just before the RSV season. 

Immunisation providers should also take into account: 

  • local RSV seasonality
  • the child’s age
  • any risk factors for severe RSV disease.

If an infant does not have risk conditions for severe RSV disease, they do not need a repeat dose, even if they received Beyfortus (nirsevimab) outside of the peak period of RSV activity.

What is the recommended dose for infants and young children receiving Beyfortus (nirsevimab)?

The dose for Beyfortus (nirsevimab) differs depending on the weight and age of the infant or child: 

  • The dose for infants weighing less than 5 kg who were born during or are entering their first RSV season is 50 mg (0.5 mL).
  • The dose for infants weighing 5 kg or over who were born during or are entering their first RSV season is 100 mg (1 mL).
  • The dose for young children entering their second RSV season is 200 mg, given as 2 intramuscular injections (2 × 1 mL of the 100 mg/mL formulation) at two different sites (preferably separate limbs, or else separated by 2.5 cm) during the same visit, regardless of weight.
What administration site is used for giving Beyfortus (nirsevimab) to infants and young children?

For young children aged less than 12 months (regardless of season), Beyfortus (nirsevimab) is given as an injection into the anterolateral aspect of the thigh.

For young children aged 12–24 months (regardless of season), Beyfortus (nirsevimab) can be given as an injection in either the anterolateral aspect of the thigh or in the deltoid muscle.

When is the Abrysvo vaccine recommended to be given to pregnant women?

Pregnant women are recommended to receive a single dose of Abrysvo vaccine from 28 weeks gestation. 

Administration prior to 36 weeks gestation is encouraged, given infants may not be well protected if they are born less than 2 weeks after their mother received the vaccine. 

If the infant is born within 2 weeks of the mother receiving the vaccine, the infant is recommended to receive a dose of the long-acting monoclonal antibody Beyfortus (nirsevimab).

Can pregnant women under the age of 18 years receive the Abrysvo vaccine?

Yes. The Abrysvo vaccine is recommended for pregnant women of all ages, including those aged less than 18 years. 

There are currently no studies of the Abrysvo vaccine in people aged less than 18 years; however, it is expected the safety and efficacy of the vaccine in people aged less than 18 years would be similar as in those aged 18 years and over.  

What should be done if Abrysvo vaccine is given to a pregnant woman before 28 weeks gestation?

If a pregnant woman is given a dose of Abrysvo before 28 weeks gestation, no further action is needed and there is no need to give another dose.

If a woman has inadvertently been given Abrysvo between 24 and less than 28 weeks gestation, they can be informed that safety data have indicated no statistically significant increase in adverse events after vaccination compared with women who received the vaccine later in pregnancy.

Can a pregnant woman receive the Abrysvo vaccine in subsequent pregnancies?

Currently, the Abrysvo vaccine is only recommended during one pregnancy. If a pregnant woman has received the vaccine during a first pregnancy and has a subsequent pregnancy, they are currently not recommended to receive another dose. A dose of Beyfortus (nirsveimab) at birth can be considered for the infant. 

Further advice on whether repeat vaccinations will be needed during subsequent pregnancies will be given once more information is available. 

How does giving Abrysvo to pregnant women help to protect newborn babies?

When a pregnant woman receives Abrysvo, her immune system produces antibodies to RSV in the first few weeks after the injection. The placenta actively transports these antibodies into the baby’s bloodstream. The antibodies help protect the infant from RSV disease once the baby is born. 

This process of providing antibodies is a form of passive immunisation.

Abrysvo provides protection to the infant for up to 6 months from birth

Can an infant, young child or pregnant woman receive an RSV immunisation product if they have previously had an RSV infection?

Yes. If a pregnant woman, infant or young child has recovered from an RSV infection, they can receive the relevant RSV immunisation product. 

Protection from RSV infection is not long-lasting and reinfection with RSV is common, so receiving an RSV immunisation product is likely to be beneficial. 

Can infants, young children and pregnant women receive an RSV immunisation product at the same time as other vaccines and medical products? 

Yes, individuals can receive RSV immunisation products at the same time as other vaccines and medical products.

Abrysvo can be given at the same time as other routine pregnancy vaccines, such as pertussis (whooping cough) and influenza vaccines. It can also be given at the same time as Anti-D immunoglobulin. 

Immunisation providers may consider giving RSV immunisation products at different visits to other vaccines to reduce the potential for mild to moderate reactions. However, this should not delay overdue or opportunistic vaccination, especially in people at high risk of severe RSV disease.

The long-acting monoclonal antibody Beyfortus (nirsevimab) can also be given at the same time as vaccines or other medical products (including vitamin K and hepatitis B immunoglobulin). Monoclonal antibodies target specific antigens, so there is unlikely to be any interference with disease antigens from other vaccines or immunisation products.

For more on these considerations, see Co-administration with other vaccines in the Australian Immunisation Handbook RSV chapter.

What should be done if an error is made in administering an RSV immunisation product to an infant, young child or pregnant woman? 

Recent reports have indicated that some RSV immunisation products have been used incorrectly. Immunisation providers should always follow the principles of ‘right product, right person, right way’ in delivering immunisation products and ensure they are familiar with all relevant guidance, especially on newer products, when administering immunisation products.

For more information on what to do if an administration error occurs, see NCIRS clinical guidance on RSV immunisation product administration errors and the TGA’s Correct administration of RSV vaccine and antibody products.

Should parents and carers of infants receive the RSV vaccine to protect infants?

A dose of an RSV vaccine is not recommended for parents and carers of infants. Currently, there are no data on the impact of vaccines on transmission of RSV infection.

How effective are RSV immunisation products at preventing severe disease in infants and young children?

Clinical trials have shown use of the Abrysvo vaccine in pregnant women provided infants with good protection from severe RSV; the risk of hospitalisation from RSV infection was reduced by around 60% in infants during their first 6 months of life. 

Effectiveness data for Beyfortus (nirsevimab) from Spain, France, and the US showed a 70–90% reduction in the incidence of RSV-related lower respiratory tract infection hospitalisation among infants during their first RSV season. 

Clinical trials of Synagis (palivizumab) in infants showed the risk of hospitalisation from RSV infection reduced by around 50%. Synagis (palivizumab) requires up to five monthly injections, however, whereas Beyfortus (nirsevimab) protects for 5 months with a single injection.

For more clinical trial data on the efficacy of RSV products that are currently in the final stages of either development or approval globally, see Table 1 in Summary of RSV immunisation product efficacy and safety [PDF].

What are the common side effects of RSV immunisation products in infants, young children and pregnant women?

In clinical trials, some pregnant women who received an RSV vaccine reported common local and generalised symptoms, including: 

  • pain and redness at the injection site
  • fatigue
  • headache
  • muscle pains. 

In clinical trials of RSV monoclonal antibodies in infants and young children, common local and generalised symptoms reported included:

  • pain, redness and swelling at the injection site
  • rash.

Across clinical trials, most side effects were mild to moderate in severity and lasted only a few days. 

For more information on clinical trial data on the safety of RSV products that are currently in the final stages of either development or approval globally, see Table 3 in Summary of RSV immunisation product efficacy and safety [PDF].

Are there any rare side effects after receiving RSV immunisation products in infants, young children or pregnant women?

A clinical trial of a now-discontinued GSK RSV vaccine for pregnant women (similar to Arexvy) found more premature births and newborn deaths in vaccinated women compared to women who had not received the vaccine, mostly in low- and middle-income countries. Because of this, rates of premature births in women who receive any RSV vaccine are being actively monitored. 

In trials for the Abrysvo vaccine, there was no clear evidence of an increase in premature births among women who had received the vaccine. Until more data are available, it is recommended that as a precaution, the Abrysvo vaccine only be given to women who are at least 28 weeks pregnant.

No rare adverse events are being monitored for the monoclonal antibody Beyfortus (nirsevimab).

Clinical trials are not designed to detect very rare serious side effects, and so large studies are needed after a vaccine is released to check if certain events happen more often in vaccinated people than in the general population. These studies are ongoing.

What is the difference between an RSV vaccine and an RSV monoclonal antibody?

The RSV vaccine ‘teaches’ the immune system to make its own antibodies against RSV by exposing it to a fragment of RSV (a protein or protein-encoding mRNA). When a vaccine is given to a pregnant woman and their immune system makes antibodies against RSV, the antibodies can be passed to their infant across the placenta to provide protection in the first few months of life.

An RSV monoclonal antibody is pre-made using recombinant technology and is given to help the body fight off RSV infection. Monoclonal antibodies start working immediately, while vaccines generally take 1–3 weeks to ‘teach’ the immune system to develop its own antibodies. 

RSV monoclonal antibodies are only for use in infants and are given as an injection into a muscle – in the same way vaccines are given.

 

Older adults

How common is severe RSV disease in older adults in Australia? 

While there are currently limited data on the RSV disease burden in adults in Australia, an NCRIS analysis [PDF] found that between 2016 and 2019 the hospitalisation rate in adults aged 60 years and over was estimated at 101 per 100,000 population. The rate was greater in those aged 75 years and over (194 per 100,000 population) compared to those aged 50–64 years (26 per 100,000 population).

Those figures are likely an underestimate, though, since RSV disease was historically seen as a disease that affects infants and children and testing for the virus in adults was previously uncommon. 

The reported rate of RSV hospitalisations in older adults has been increasing with the growing awareness of RSV disease and more frequent laboratory testing in this age cohort.

Which adults are at greatest risk of requiring hospitalisation with RSV disease?

The risk of severe RSV disease is higher among: 

  • older adults (with the risk increasing with age)
  • adults with medical risk conditions
  • Aboriginal and Torres Strait Islander adults.

For non-Indigenous adults, the risk is greater from age 75, while for Aboriginal and Torres Strait Islander adults and adults with risk conditions the risk is greater from 60 years of age. 

Examples of medical risk conditions for severe RSV disease include: 

  • chronic cardiac, respiratory, neurological and liver conditions
  • immunocompromising conditions
  • chronic metabolic disorders
  • chronic kidney disease
  • obesity.
What RSV vaccines are available to protect older adults from severe RSV disease?

Currently, two RSV vaccines – Arexvy and Abrysvo – have been approved by the TGA in Australia for older adults for protection against severe RSV disease. 

RSV vaccines for older adults are not funded on the NIP. 

RSV immunisation with Arexvy is funded for Victorian residents aged 60 years and over in public and Aboriginal community-controlled aged care services.

For more information on the status of these and other RSV immunisation products in Australia, see Evaluation of and expected access to new RSV vaccines and long-acting monoclonal antibody (mAB) in Australia [PDF].

Which older adults are recommended to receive an RSV vaccine?

In Australia, RSV vaccine is recommended for:

  • all people aged 75 years and over
  • people aged 60 years and over with conditions that increase their risk of severe RSV
  • Aboriginal and Torres Strait Islander adults aged 60 years and over. 

All other adults aged 60–74 years can also consider receiving an RSV vaccine. 

Adults aged 50–59 years with conditions that increase their risk of severe RSV disease can also consider receiving the Arexvy vaccine.

People aged less than 60 years who do not have conditions that increase their risk of severe RSV disease are not eligible to receive an RSV vaccine, and the TGA has not registered any vaccines for use in this population.

For more information on these recommendations, including the medical conditions associated with an increased risk of RSV disease complications, see the Australian Immunisation Handbook RSV chapter.

Are booster doses of RSV vaccine recommended for older adults?

The need for future booster doses of RSV vaccine has not yet been established. Currently, only a single dose is recommended.  

Recommendations on the need for any subsequent doses will be provided when evidence is available.

What are the common side effects of RSV vaccines in older adults?

In clinical trials, some older adults who received an RSV vaccine reported common local and generalised symptoms, including: 

  • pain and redness at the injection site
  • fatigue
  • headache
  • muscle pains. 

Across clinical trials, most side effects were mild to moderate in severity and lasted only a few days. 

AusVaxSafety data show 33% of people who received a dose of Arexvy and completed an AusVaxSafety survey reported some form of adverse event, with the most common being a local reaction. 

For more information on clinical trial data on the safety of RSV products that are currently in the final stages of either development or approval globally, see Table 3 in Summary of RSV immunisation product efficacy and safety [PDF].

Are there any rare side effects after receiving an RSV vaccine in older adults?

Clinical trials are not designed to detect very rare serious side effects, and so large studies are needed after a vaccine is released to check if certain events happen more often in vaccinated people than in the general population. 

Early data from the US for adults aged 60 years and over suggest Guillain-Barré Syndrome (GBS), a neurological condition associated with muscle weakness, might occur more often than expected after receipt of the Abrysvo or Arexvy vaccines. The rate of GBS was found to be around 7–9 cases per million doses in the first 1–42 days after vaccination, compared to the expected rate of 2 cases per million doses. However, GBS is still very rare, and these findings require ongoing analyses and monitoring.

Can an older adult receive an RSV vaccine at the same time as other vaccines?

Yes, individuals can receive an RSV vaccine at the same time as other vaccines.  

Arexvy and Abrysvo can be given at the same time as other vaccines for older adults, such as COVID-19, influenza (including adjuvanted influenza), pneumococcal and shingles vaccines. 

Immunisation providers may consider giving RSV vaccines at different visits to other vaccines to reduce the potential for mild to moderate reactions. However, this should not delay overdue or opportunistic vaccination, especially in people at high risk of severe RSV disease.

For more on these considerations, see Co-administration with other vaccines in the Australian Immunisation Handbook RSV chapter.

Can an older adult receive an RSV vaccine if they have previously had an RSV infection?

Yes. If an older adult has recovered from an RSV infection, they can receive an RSV vaccine. 

Protection from RSV infection is not long-lasting and reinfection with RSV is common, so receiving an RSV vaccine is likely to be beneficial.

How effective are RSV vaccines at preventing severe disease in older adults?

Data on the effectiveness of RSV vaccines come from clinical trials. Real-world effectiveness studies are currently underway in countries where these products have been in use since late 2023. 

Clinical trials for Arexvy, Abrysvo and mRESVIA (Moderna; not yet available in Australia) showed good protection against severe RSV disease in adults aged 60 years and over, with around a 60–90% reduction in the risk of severe lower respiratory tract disease in vaccinated individuals. In adults aged 50–59 years with medical conditions that increased their risk of severe RSV, a clinical trial showed the immune response following vaccination with Arexvy was similar compared to adults aged 60 years and over.

For more clinical trial data on the efficacy of RSV products that are currently in the final stages of either development or approval globally, see Table 2 in Summary of RSV immunisation product efficacy and safety [PDF].

 

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