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

Icon image: vaccine vial
Icon image: vaccine vial

Key points

  • Respiratory syncytial virus (RSV) is a common virus that can infect people of all ages. It is most serious in infants, young children and older adults, who are the focus for preventative strategies. 
  • RSV can cause a range of respiratory illnesses – from mild colds to severe 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. 
  • Arexvy and Abrysvo, which are both non-live vaccines, are the two RSVs vaccines currently registered and approved for use in Australia. They are both approved for use in people aged 60 years and over. Arexvy is not registered for use in people aged less than 60 years or in pregnancy. Abrysvo is registered for use in pregnant women but is not registered for use in non-pregnant people aged less than 60 years.
  • Arexvy is recommended for people aged 75 years and over, First Nations people aged 60 years and over, and adults aged 60 years and over with medical conditions that increase their risk of severe RSV disease. For further information, see the ATAGI statement on the clinical use of Arexvy.
  • Another RSV vaccine is currently being evaluated for registration for use in older adults in Australia. Passive immunisation of infants is possible using monoclonal antibodies that contain pre-made antibodies and can prevent severe RSV disease. 
  • Beyfortus (nirsevimab) is a new long-acting monoclonal antibody product that the Therapeutic Goods Administration (TGA) has recently registered for use in: (i) infants from birth (as a single injection); and (ii) children in the second year of life who have risk conditions for severe RSV. 
  • Another monoclonal antibody, Synagis (palivizumab) – which is given as a monthly injection and is approved for use in children at risk of severe RSV disease – has been available for many years. 
  • Beyfortus (nirsevimab) is currently only available to infants and children through state-managed programs in Western Australia, Queensland and New South Wales, and eligibility varies across these states. For further information, see the ATAGI statement on nirsevimab 2024.
  • RSV monoclonal antibody products are not registered in Australia for use in anyone older than 24 months.  
  • Access to all RSV prevention products is currently limited; none are part of the National Immunisation Program (NIP). 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
     

This resource is being updated regularly as new developments in product availability and funding occur.

Last updated: 10 April 2024


What is RSV disease?

RSV is a common virus that can infect people of all ages. It can cause a range of respiratory illnesses – from mild colds to severe conditions like bronchiolitis, bronchitis or 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 do you get RSV?

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.

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. 

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 this period was approximately 6,200 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?

Those 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 disease
  • infants and young children aged 2 years and under who were born pre-term or with a low birth weight.

First Nations 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.


How common is severe RSV disease in older Australian adults? 

While there are currently limited data on the RSV disease burden in adults in Australia, between 2016 and 2019 the hospitalisation rate in adults aged 65 years and older was estimated at 123 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).

This figure is likely an underestimate, however, since RSV disease was historically regarded 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: 

  • adults with medical risk conditions 
  • older adults (with the risk increasing with age). 
  • First Nations adults.

For non-First Nations adults, the risk is greater from age 75, while for First Nations adults and adults with medical risk conditions the risk is greater from age 60. 

Examples of medical risk conditions for severe RSV disease include: 

  • chronic cardiac, respiratory and neurological conditions
  • immunocompromising conditions
  • chronic metabolic disorders 
  • chronic kidney disease.

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

Globally, two types of RSV monoclonal antibody products are available for administration to infants and one RSV vaccine is available for administration to pregnant women. Both of these options are designed to protect infants against severe RSV disease through passive immunisation – that is, by providing RSV antibodies to the infant either across the placenta (a high level of antibody is generated from vaccination of the pregnant women) or by injection of the infant with a monoclonal antibody. 

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 TGA in March 2024. The same vaccine is also registered for use in older adults aged 60 years and over. 
  • Beyfortus (nirsevimab) is a new long-acting monoclonal antibody that was registered by the TGA in November 2023 for use as a single injection in infants. It is currently only available in Western Australia, Queensland and New South Wales. 
  • Synagis (palivizumab) has been registered for use in infants aged 24 months and under for many years; however, it needs to be given monthly. Each dose provides 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.


Who is eligible to receive the infant monoclonal antibody Beyfortus (nirsevimab)?

Eligibility to receive Beyfortus (nirsevimab) varies across jurisdictions. Some states have introduced state-based RSV programs offering Beyfortus (nirsevimab) to eligible infants, as follows:

Infants and children in other states and territories are currently not eligible to receive Beyfortus (nirsevimab). 

Further details can be found in the ATAGI statement on nirsevimab 2024.


How does giving the RSV vaccine to pregnant women help to protect newborn babies?

When a pregnant woman receives an RSV vaccine, her immune system produces antibodies to RSV in the first few weeks after the injection, and these are actively transported by the placenta into the baby’s bloodstream. These antibodies help protect the infant from RSV disease once the baby is born. This process of providing antibodies is a form of passive immunisation.

The current maternal RSV vaccine provides protection to the infant for up to 6 months from birth.


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 protein (or protein-encoding mRNA). 

A monoclonal antibody against RSV is pre-made using recombinant technology and is given to help the body fight off an infection. Monoclonal antibodies start working within a couple of days, 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. They are not licensed for use in adults. 

The RSV vaccine given to pregnant women to protect their infant against severe RSV is also given as an injection into a muscle.


What RSV vaccines are available to protect older adults from severe RSV disease?

Vaccines are the only RSV immunisation products available for older adults for protection against severe RSV disease. 

Currently, two RSV vaccines have been approved by the TGA  in Australia; one vaccine is currently under evaluation:

  • Arexvy is registered for use for adults aged 60 years and over (currently available)
  • Abrysvo is registered for use in adults aged 60 years and over (not yet available). It is also registered for use in pregnant women
  • Moderna (trade name to be confirmed) is under evaluation.

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


Who is recommended to receive the RSV vaccine Arexvy (for older adults)?

In Australia, Arexvy (RSV vaccine for older adults only) is recommended for:

  • all people aged 75 years and over 
  • people aged 60–74 years with medical conditions that increase their risk of severe RSV
  • First Nations adults aged 60–74 years. 

All other adults aged 60–74 years can also consider receiving Arexvy. 

People aged less 60 years are not eligible to receive Arexvy, which the TGA has not registered for use in this age group.

For further information on these recommendations, including the medical conditions associated with an increased risk of RSV disease complications, see the ATAGI statement on the clinical use of Arexvy.


Are booster doses of Arexvy recommended for older adults?

The need for future booster doses has not yet been established. Recommendations on the need for subsequent doses will be provided when evidence is available.


Who is eligible to receive a free RSV immunisation product?

In Australia, no RSV vaccines are currently funded under the NIP. Arexvy is the only vaccine registered for use in Australia, and it is only available via private purchase.  

Currently, there are three state-funded programs  for the monocloncal antibody product Beyfortus (nirsevimab) for infants:


What are the common side effects of RSV prevention products?

In clinical trials, older adults and 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, 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 further 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.


Can a person receive an RSV immunisation product at the same time as other vaccines?

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

Arexvy 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.

Providers may consider giving Arexvy 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 disease.

For more information on these considerations, see the ATAGI statement on the clinical use of Arexvy.

Beyfortus (nirsevimab) can be given at the same time as other vaccines for infants and young children.


Can a person receive an RSV immunisation product if they have previously had an RSV infection?

Yes. If a person is not currently unwell and has previously had an RSV infection, they can receive the relevant RSV immunisation product. Protection from natural infection is not long-lasting and reinfection with RSV is common, so receiving an RSV immunisation product is likely to be beneficial.

In New South Wales, infants who have had prior laboratory-confirmed RSV infection in 2024 are not eligible for a state-funded dose of Beyfortus (nirsevimab).


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

Data on the effectiveness of RSV immunisation products come from clinical trials. Real-world effectiveness studies are currently underway. 

Clinical trials have shown that: 

  • 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 
  • use of RSV monoclonal antibodies (Synagis and Beyfortus) in infants also provides a similar level of protection in their first 5 months of life; the risk of hospitalisation from RSV infection is reduced by almost 80% with Beyfortus (nirsevimab) and by around 50% with Synagis (palivizumab) in infants. However, Synagis (palivizumab) requires up to five monthly injections, while 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.


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

Data on the effectiveness of RSV immunisation products 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 (not yet available in Australia) and Moderna (trade name to be confirmed; not yet available in Australia) showed good protection against severe RSV disease in adults aged 60 years and over, with around an 80–95% reduction in the risk of severe lower respiratory tract disease in vaccinated individuals. 

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.


What other RSV prevention products are under development?

Details about worldwide RSV clinical trials that are currently underway are available via the PATH RSV clinical trial tracker