What is the difference between nirsevimab and the maternal RSV vaccine?

The maternal RSV vaccine (RSVpreF/Abrysvo) is given to the pregnant person, with antibodies passing to the baby before birth. Nirsevimab is given directly to the infant as a monoclonal antibody injection. They are complementary strategies — nirsevimab covers babies who miss out on full maternal antibody transfer.

Is nirsevimab available in Australia now?

Yes, but inconsistently. Nirsevimab is currently funded through separate state and territory programs with different eligibility criteria. Some states fund it only for high-risk infants; some do not fund it at all. The PBAC recommendation, if accepted, would standardise national access from February 2027.

What should I do if I am pregnant now?

Ask your GP or obstetrician about the National RSV Mother and Infant Protection Program (RSV-MIPP) timing. This maternal vaccination program is currently running and is the primary strategy for protecting your newborn against RSV.

Nirsevimab recommended for the National Immunisation Program

RSV — respiratory syncytial virus — is the leading cause of hospitalisation in children under two in Australia. Most children will have had at least one RSV infection by age two, and for healthy term infants, it usually means a week of difficult cold symptoms and close monitoring at home. For premature babies, infants with congenital heart disease, and those with underlying respiratory conditions, it can mean intensive care admission.

The immunisation landscape for RSV has changed significantly over the past two years. The National RSV Mother and Infant Protection Program (RSV-MIPP) provides maternal vaccination with RSVpreF (Abrysvo) to protect newborns via passive antibody transfer. Nirsevimab offers a complementary pathway — a direct monoclonal antibody injection for the infant, providing around four months of protection against severe RSV disease.

This week, the PBAC recommended that nirsevimab be added to the National Immunisation Program.

What the recommendation covers

The PBAC’s September 2026 intracycle recommendation covers two groups:

Infants who may have been missed by maternal RSV vaccination — particularly those born within two weeks of their mother receiving the RSVpreF vaccine, before full antibody transfer has occurred. And infants at continued risk of severe RSV disease: those in their first RSV season despite maternal vaccination, and children up to two years of age through their second season.

A legislative amendment earlier this year broadened the definition of a vaccine to include passive immunisation strategies like nirsevimab — which is technically a monoclonal antibody, not a vaccine, but confers protection in a comparable way. That definitional change cleared the regulatory pathway for this NIP recommendation.

The problem with the current access patchwork

Right now, nirsevimab is funded through separate state and territory programs with different eligibility criteria in each jurisdiction. Some states fund it for high-risk infants only. Some do not fund it at all. A premature baby in one state may have funded access that a similarly premature baby in another state doesn’t.

Dr Tim Jones from the RACGP described the current system as “confusing.” From a family’s perspective, that understates it. The current landscape requires knowing which state you’re in, what program applies to your baby’s gestational age and clinical history, whether your baby qualifies, and where to go. For new parents navigating hospital discharge with a premature or high-risk infant, that is a meaningful barrier.

Dr Rod Pearce from the GP and Immunisation Coalition welcomed the recommendation as “interesting and appropriate,” while raising a practical concern: supply delays affected recent Shingrix and pneumococcal vaccine rollouts, and the timeline here matters. The recommendation specifies the government should have nirsevimab on the NIP by February 2027 — the start of the next RSV season. Whether supply chains can be established in time is an open question.

Both-and: a genuine advance and an implementation question

The PBAC recommendation is genuinely good news. Adding nirsevimab to the NIP would replace the current patchwork with consistent national access — meaning a baby born in any state would have the same pathway to protection, regardless of jurisdiction.

The honest caveat is that PBAC recommendations are not NIP listings. The federal government must accept the recommendation and fund the program. No implementation date has been announced, and the supply chain concern Dr Pearce flagged is worth taking seriously given recent experience with other vaccine rollouts.

For families expecting a baby now, the maternal RSV vaccination program is running and is the primary protection strategy. Asking your GP or obstetrician about RSV-MIPP timing — particularly the optimal window in pregnancy — is the relevant action today.

Nirsevimab as a NIP-funded option would extend and complement that protection. The recommendation moves the landscape forward; implementation is what delivers the outcome.

2 cents

If you have a baby under two, or are expecting, the RSV protection landscape is meaningfully better than it was three years ago. The maternal vaccination program is running. The prospect of nationally consistent nirsevimab access is the closest it has been.

The practical questions to ask now: if you are pregnant, discuss RSV-MIPP timing with your GP or obstetrician. If your baby is premature, has a cardiac condition, or has respiratory vulnerabilities, ask specifically about nirsevimab access in your state and whether your baby qualifies under the current program — while the federal government considers the NIP listing, some state programs remain open.

Verdict: yes — a meaningful step toward nationally consistent RSV protection for vulnerable infants, time-sensitive given the February 2027 RSV season deadline.