Understanding the New RSV Options for Pregnant Mums and Babies

Introduction:

RSV, or respiratory syncytial virus, is a super common virus that affects people of all ages. For most of us, it’s just an annoying cold. But for babies, especially those under 6 months, it can be more serious. This is because their tiny little airways make them more vulnerable to breathing issues like bronchiolitis and pneumonia (to learn more on recognising respiratory distress in your baby, see here).

RSV spreads through droplets from coughs and sneezes, and it can survive on surfaces for hours- so as you can imagine, it’s impossible to avoid completely.

Recently in Australia, new RSV protection options have been rolled out for babies. But along with this rollout has come a fair bit of confusion around what these products are, and who can actually receive them.

This post breaks it all down: how common RSV is, who’s most at risk, what’s now available, and who is eligible.

How common is RSV?

Did you know that almost every child will have had at least one RSV infection by their second birthday?? It’s that common! And while most children recover just fine, some babies are more at risk of developing serious illness.

Those most at risk include:

• Babies under 6 months (especially 0–2 months old)
• Premature or low birthweight babies
• Children under 2 with chronic lung or heart issues
• First Nations babies and toddlers under 2

What protection options are available for babies and young children?

What’s important to understand is that the new options don’t stop RSV completely- their role is to help protect babies from becoming seriously unwell or needing hospital care.

There are two main products being used:

1️⃣ An RSV vaccine given to pregnant mothers (to protect babies before birth)

2️⃣ A monoclonal antibody given directly to babies after birth (for added protection during RSV season)

Let’s go through both.

RSV Vaccine for Mothers (Abrysvo)

What is it? Abrysvo is offered between 28 and 36 weeks of pregnancy. It helps your body make antibodies to RSV. Those antibodies are passed to your baby through the placenta a process called passive immunisation which helps protect them during the early most vulnerable months of life.

Because your body needs time to make and transfer those antibodies, the vaccine isn’t recommended after 36 weeks.

It’s safe to have Abrysvo at the same time as your flu shot, whooping cough vaccine, or Anti-D. It’s also approved for younger pregnant people, including teens.

Unlike whooping cough and flu vaccines, Abrysvo isn’t recommended for partners or other carers. It’s designed to protect the baby, not to stop RSV spreading.

How effective is it? Clinical trials showed a 60% reduction in RSV-related hospitalisations for babies in their first six months of life.

Common side effects can include:

• Sore arm
• Feeling tired
• Headache
• Mild muscle aches

What about that discontinued RSV trial? You might have heard about an older RSV vaccine trial that was stopped because of a possible link to premature birth. That was a different product (not Abrysvo). In its clinical trials, no increased risk of premature birth was found with Abrysvo.

RSV Antibody for Babies (Beyfortus)

What is it? Beyfortus is a monoclonal antibody not a vaccine. Vaccines train the immune system to make antibodies. Monoclonal antibodies, like Beyfortus, skip that step: they give the baby ready made antibodies to provide immediate protection.

Beyfortus is given as a one-off injection to babies after birth.

Who can get it? Beyfortus is offered to:

• Babies whose mums didn’t receive Abrysvo
• Babies born less than 2 weeks after mum received Abrysvo
• Babies whose mothers were severely immunocompromised during pregnancy
• Babies who’ve had certain medical procedures
• Babies and toddlers under 2 with some medical conditions

Could a baby need a second dose? Some children aged 8 to 24 months who are at higher risk of severe RSV might be offered a second dose before their next RSV season, even if they’ve already had Beyfortus or mum had the vaccine during pregnancy. For most healthy babies, though, one dose is enough.

How effective is it? Studies from Spain, France and the US showed a 70–90% reduction in RSV hospitalisations in a baby’s first RSV season.

Common side effects may include:

• Redness or swelling where the injection was given
• Rash
• Fussiness or irritability

Beyfortus can be given at the same time as your baby’s other routine vaccines.

What about Synagis? You may have heard about another monoclonal antibody called Synagis (palivizumab) which has been around for a while. It’s still used for some high-risk infants, but it has to be given monthly during RSV season. Beyfortus only needs one dose to cover the season.

Final Thoughts:

RSV is very common, and most babies who catch it will recover well. But for some especially younger or medically vulnerable babies it can lead to more serious illness.

That’s why Australia is now offering:

• Abrysvo: an RSV vaccine given during pregnancy
• Beyfortus: a monoclonal antibody for babies after birth

If you’re unsure about any of this- don't ever feel afraid to ask questions! It is all new and there is a lot of misinformation online. Chat with your doctor or midwife and they can guide you based on your individual situation.

And if this info helped you feel a bit clearer, consider sharing it with a friend who might be feeling just as confused.