What’s the fuss about the RSV vaccine?

There is a lot in the media at the moment about the RSV vaccine, so what is it and what do you need to know about it?

RSV stands for respiratory syncytial virus (RSV). It is a common virus in Australia that is highly contagious. It is spread through tiny droplets in the air from an infected or a surface that has become contaminated.

People are most infectious when they have symptoms but can be infectious before they have symptoms.

RSV may be mild in someone who is healthy and has a strong immune system. However, in people with weakened immune systems it can be very dangerous.

People who are at the highest risk of RSV include

• Babies under 12 months of age, especially those under 6 months of age

• Children under 2 years of age with chronic medical conditions such as congenital heart disease or chronic lung diseases such as Cystic Fibrosis

• Children under 2 years who were born prematurely (before 32 weeks)

• Adults with chronic heart or lung disease, cancer, or chronic immune deficiency

The most common symptoms of RSV are a runny nose, cough, wheeze, fever and difficulty breathing. If you or your child are asthmatic, infection with RSV may trigger an asthma attack.

The reason why RSV is such a concern in babies under 12 months of age is because it can lead to pneumonia, or bronchiolitis (inflammation of the airways). Both can lead to severe breathing problems which may require hospitalisation. RSV infection can also increase the risk of asthma in children and adults.

The reason RSV has been in the news so much of late is because in NSW, the RSV vaccine (Abrysvo) is now available under the National Immunisation Program (NIP) for pregnant women. Women between 28-36 weeks gestation can now receive the vaccine free from their GP to protect their newborn babies from RSV. When pregnant mothers are vaccinated, they will pass antibodies to their babies via the placenta and research has shown that this can reduce the risk of severe RSV disease and hospitalisation in infants less than six months of age by approximately 70%.

Abrysvo works by teaching your immune system to mount an immune response to RSV. It has proteins which are found on the actual RSV virus itself. When injected into your body, your immune system recognises these and makes antibodies to fight RSV. Thus, if you are subsequently infected with the RSV virus your immune system will already be equipped with antibodies to protect you against the virus. These antibodies are passed to your unborn child. This vaccine usually takes about 2 weeks to work.

The RSV vaccine can be given with the influenza vaccine and the whooping cough vaccine.

Starting from March 17, 2025, NSW will also offer nirsevimab (Beyfortus), a monoclonal antibody, to infants who are not protected through maternal vaccination or who have risk factors for severe RSV disease. This will include babies born to mothers who were vaccinated with RSV less than 2 weeks before giving birth or babies whose mothers were vaccinated with RSV but who have very weak immune systems. The aim of this is to ensure that all vulnerable infants across the state are offered adequate protection from RSV infection and its dangerous sequelae.

This treatment works differently to the maternal vaccine. Antibodies are part of our immune system which seek out antigens or foreign materials which make us sick, like the proteins on RSV. A monoclonal antibody means that we are injecting exact copies of the antibody the human immune system would make to the baby allowing their immune system to recognise and fight RSV if they are exposed to it. This vaccine is effective immediately.

For older adults, while vaccines like Arexvy have been approved by the Therapeutic Goods Administration (TGA) for individuals aged 60 years and over, they are not currently funded under the NIP. As a result, older adults may need to pay for the vaccine out-of-pocket, with costs around $350. There are ongoing discussions and reviews regarding the inclusion of RSV vaccines for older adults in the NIP.

We currently recommend Arexvy 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.

A booster dose is not required. We have good evidence that the vaccine lasts at least 24 months but we need more more data to be collected for us to advise after this timeframe. The best time of the year to receive the vaccination is Autumn to get the maximum benefit for Winter.

Side effects of all of these vaccines include a rash, muscle soreness and redness and they can all be given even if you have had previous RSV infection.

What if you or your baby do get RSV?

• It is generally diagnosed with a throat swab done by your GP, although can be diagnosed just by clinical signs and symptoms

• It may be managed at home depending on the severity of the symptoms

For adults

• Rest

• Hydration

• Paracetamol and ibuprofen as needed

For babies

• Continue breastfeeding, you may need to give smaller amounts more frequently

• If you notice

 reduced wet nappies

 fevers which do not come down with Panadol

 difficulty breathing

 breathing interfering with feeding

 grunting

 dehydration

 blue lips

you need to call 000 or go to ED immediately

So, what is our take home message?

• Protect your pregnancy: ask your GP if you are eligible for the RSV vaccine during your pregnancy. This will provide your baby the best protection right from birth.

• Protect your baby: ask your GP if your baby is eligible for the RSV vaccine if they are already born or may be eligible for a catch-up vaccine.

• Practice good hygiene around your pregnancy, baby and home: Handwashing, avoiding sick contacts, asking people to cover their nose and mouth when they sneeze, and avoiding crowded places with poor ventilation.

References:

1. NSW Health [3/02/25]

https://www.health.nsw.gov.au/immunisation/pages/abrysvo.aspx

https://www.health.nsw.gov.au/Infectious/factsheets/Pages/respiratory-syncytial-virus.aspx

https://www.health.nsw.gov.au/immunisation/pages/nirsevimab-parents-and-carers.aspx

2. National Centre of Immunisation and Research Surveillance https://immunisationhandbook.health.gov.au/contents/vaccine-preventable-diseases/respiratory-syncytial-virus-rsv#vaccines-dosage-and-administration [3/02/25]

3. Therapeutic Goods Administration https://www.ebs.tga.gov.au/ebs/picmi/picmirepository.nsf/pdf?OpenAgent&id=CP-2023-PI-02637-1 [3/02/25]

4. Australian Immunisation Handbook https://immunisationhandbook.health.gov.au/contents/vaccine-preventable-diseases/respiratory-syncytial-virus-rsv#vaccines-dosage-and-administration [3/02/25]