Maternal jabs reduce RSV hospitalisations by 80%

Published in JAMA Paediatrics, the findings come from one of the largest national evaluations of maternal RSV vaccination since the vaccine was introduced under the National Immunisation Program in early 2025.

The analyses, undertaken by The Kids Research Institute Australia, included 1012 infants hospitalised with acute respiratory illness (ARI) across nine Australian hospitals.

The results showed that RSV vaccination during pregnancy offered high and sustained protection against hospitalisation and severe forms of the respiratory diseases caused by RSV in infants through six months of age.

Protection was highest during the earliest months of life, when babies were most vulnerable to serious RSV infection.

In infants through to two months of age, vaccine effectiveness against hospitalisations for RSV-related lower respiratory tract disease was 86.3%.

Protection remained consistently high regardless of when the vaccine was given during the recommended pregnancy window (from 28 weeks of gestational age) or whether it was administered alongside other routine maternal vaccines.

Clinician-scientist at the Wesfarmers Centre of Vaccines and Infectious Diseases Dr Ushma Wadia said the results showed Australia's Maternal and Infant RSV Protection Program (RSV-MIPP) was doing exactly what it was designed to do.

“This represents some of the strongest real-world evidence demonstrating that maternal RSV vaccination is working in Australia," she said.

“The findings show the vaccine can be effectively incorporated into routine antenatal care pathways, including alongside other recommended pregnancy vaccines, giving general practitioners, obstetricians, midwives and families confidence that we have an effective RSV prevention strategy to reduce the burden of severe RSV-related disease in our youngest babies.”

Lead researcher Dr Ushma Wadia, clinician-scientist at the Wesfarmers Centre of Vaccines and Infectious Diseases, based at The Kids.

The findings build on The Kids Research Institute Australia’s internationally recognised RSV research.

In May, it was demonstrated that Australia's RSV-MIPP – combining maternal vaccination during pregnancy and immunisation for babies – cut hospital admissions for Australia’s youngest babies by almost half in its first year, providing strong early evidence of the program’s effectiveness.

Researchers will continue to evaluate vaccine effectiveness, with future analyses using larger sample sizes to evaluate protection across different infant subgroups, protection beyond six months of age and for infants born out of RSV season.