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 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. 
     
  • A single dose of RSV vaccine (Arexvy or Abrysvo) 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 conditions that increase their risk of severe RSV disease
     
  • A single dose of Abrysvo is recommended for pregnant women at 28–36 weeks gestation to protect the infant via passive immunisation.
     
  • Passive immunisation of infants is also possible using monoclonal antibodies that contain pre-made antibodies and can prevent severe RSV disease. 
     
  • Beyfortus (nirsevimab) is a new long-acting monoclonal antibody recommended in certain infants and children. It is currently only available to infants and children through state-managed programs in Western Australia, Queensland and New South Wales; eligibility varies across these states. 
     
  • Another monoclonal antibody, Synagis (palivizumab), is approved for use in children at risk of severe RSV disease and has been available in Australia for many years. 
     
  • No RSV prevention products are funded under 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: 5 July 2024

The Australian Immunisation Handbook RSV chapter was published on 27 June 2024.

FAQs


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 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?

Two types of RSV monoclonal antibody products are available for administration to infants; 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 (whereby a high level of antibody is generated from vaccination of the pregnant woman) 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 Therapeutic Goods Administration (TGA) in March 2024
  • Beyfortus (nirsevimab), a new long-acting monoclonal antibody, 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 recommended to receive the infant long-acting RSV monoclonal antibody Beyfortus (nirsevimab)?

Beyfortus is recommended for the following infants and young children:

  • 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 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

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 do not currently have access to Beyfortus (nirsevimab). 

Further details can be found in the Australian Immunisation Handbook RSV chapter.


When is Abrysvo recommended to be given to pregnant women?

Pregnant women are recommended to receive a single dose of RSV vaccine (Abrysvo) at 28–36 weeks gestation.


What should be done if the RSV vaccine (Abrysvo) 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 compared with women who received the vaccine later in pregnancy.


Should a pregnant woman still receive the RSV vaccine (Abrysvo) if they are beyond 36 weeks gestation?

Yes: if a pregnant woman is beyond 36 weeks gestation, they should still receive Abrysvo. 

If the infant is born within 2 weeks of the mother receiving the vaccine, the infant may not be well protected. In these circumstances, the infant is recommended to receive a dose of long-acting monoclonal antibody (Beyfortus [nirsevimab]).


What should be done if the wrong RSV vaccine is given to a pregnant woman?

Arexvy is not registered for use in pregnant women and should not be given to pregnant women. There is limited data on inadvertent administration in pregnancy. If a pregnant woman has been given Arexvy inadvertently, seek advice from your state or territory health authority. (Find your specialist immunisation service here.)


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. 


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). When a vaccine is given to a pregnant woman and their immune system makes antibodies against RSV, these can be passed to their infant across the placenta to provide protection in the first few months of life.

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.


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. 

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.


Who is recommended to receive RSV vaccine for older adults?

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
  • First Nations adults aged 60 years and over. 

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

People aged less than 60 years are not eligible to receive an RSV vaccine, and the TGA has not registered any vaccines for use in this age group.

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. 


Who is eligible to receive a free RSV immunisation product?

In Australia, no RSV vaccines are currently funded under the NIP. The RSV vaccines Arexvy and Abrysvo are only available via private purchase. 

Currently, three state-funded programs are providing free monoclonal 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 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. 

Abrysvo (the only vaccine available for pregnant women) can be given at the same time as other routine pregnancy vaccines, such as pertussis and influenza. 

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 the ATAGI statement on the clinical use of Arexvy.

The long-acting monoclonal antibody Beyfortus (nirsevimab) can also be given at the same time as 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 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. 

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 and mRESVIA (Moderna; 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