Australia’s RSV Maternal and Infant Protection Program is delivering exactly the results it was designed for, with new research showing RSV vaccination during pregnancy reduces the risk of RSV-related hospitalisation by more than 80% in an infant’s first 6 months of life.
Published in JAMA Pediatrics, the findings come from the STREETON study, reportedly one of the largest national studies of maternal RSV vaccination conducted since the vaccine joined the National Immunisation Program (NIP) in early 2025.
Researchers from The Kids Research Institute Australia analysed 1012 infants hospitalised with acute respiratory illness across 9 Australian hospitals.
Protection strongest in the earliest months
The study’s results reveal the vaccine given during pregnancy offers “high and sustained protection against hospitalisation and severe forms of respiratory disease caused by RSV in infants”.
The results show the vaccine is:
- “80.8% effective at reducing RSV-related hospitalisations.”
- “77.8% effective at reducing hospitalisations for RSV-related lower respiratory tract disease.”
- “80.4% effective at reducing hospitalisations for severe RSV-related lower respiratory tract disease.”
According to the researchers, “protection is highest in the earliest months of life” — “in infants through to 2 months of age, vaccine effectiveness was 86.3%”.
Notably, the researchers say “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”.
“Doing exactly what it was designed to do”
Dr Ushma Wadia, clinician-scientist at the Wesfarmers Centre of Vaccines and Infectious Diseases, says the results reflect the program’s success and that it’s “doing exactly what it was designed to do — protecting young babies from serious RSV illness”.
“This represents some of the strongest real-world evidence demonstrating that maternal RSV vaccination is working in Australia,” says Dr Wadia, who is a paediatrician at Perth Children’s Hospital and a clinical senior lecturer at the University of Western Australia’s Medical School.
“Importantly, 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.”
Researchers plan further analyses to assess protection beyond 6 months and across infant subgroups.
They say the findings will help guide ongoing efforts to protect babies from severe RSV disease.
