– ESCMID Global: Maternal vaccination against RSV reduces the risk of childhood hospitalization by more than 80%, according to a major UKHSA study
/PRNewswire/ — The largest real-world study of its kind, presented today at ESCMID Global 2026, demonstrates that maternal vaccination against respiratory syncytial virus (RSV) reduces the risk of hospitalization in infants by more than 80% when administered at least two weeks before birth.
RSV is a common virus that can cause serious respiratory illnesses in infants and young children, including lower respiratory tract infections (LRTIs) such as bronchiolitis and pneumonia. It is a leading cause of childhood hospitalization worldwide, and infection in early childhood is associated with potential long-term effects, such as recurrent wheezing or asthma, hospital readmissions, and deterioration in lung health.
In England, a national RSV maternal vaccination program was launched on 1 September 2024, offering the bivalent Prefusion F vaccine to pregnant women from 28 weeks’ gestation.
To assess its impact on childhood hospitalizations for lower respiratory tract infections associated with respiratory syncytial virus (RSV), researchers from the United Kingdom Health Security Agency (UKHSA) carried out a retrospective cohort study using linked national datasets, including National Health Service (NHS) maternity records, vaccination data, and hospital and laboratory data. The analysis included 289,399 babies born between September 2, 2024 and March 24, 2025, representing approximately 90% of births in England during this period.
In the population studied, 4,594 hospitalizations associated with RSV were recorded. Although infants born to unvaccinated mothers represented 55% of the total cohort, they accounted for 87.2% of hospitalizations.
In contrast, babies whose mothers were vaccinated at least 14 days before delivery had a markedly lower risk of hospitalization, with vaccine effectiveness estimated at 81.3%, compared to the unvaccinated group.
Lead author and UKHSA epidemiologist Matt Wilson commented: “As the largest study to date of the impact of this vaccine on childhood hospitalization, these findings provide strong evidence that vaccination offers substantial protection against serious disease in infants. We found a clear relationship between the timing of vaccination and protection, with effectiveness increasing as the interval between vaccination and birth lengthens, reaching almost 85% when vaccination is carried out at least four weeks before birth.”
The study also investigated outcomes in premature babies. The effectiveness of the vaccine was estimated at 69.4% in premature babies, when at least 14 days were allowed to elapse between vaccination and birth.
“These findings are especially important for premature babies, who are among the most vulnerable to severe respiratory syncytial virus (RSV) infection,” Wilson added. “With sufficient time between vaccination and birth, we saw good levels of protection in these babies.”