Maternal RSV Vaccine Cuts Infant Hospitalization Risk by 72% in Real-World UK Study
First real-world evidence shows maternal RSV vaccination during pregnancy dramatically reduces severe respiratory illness in newborns.
Summary
A groundbreaking UK study of 537 mother-infant pairs demonstrates that maternal RSV vaccination during pregnancy reduces infant hospitalization risk by 58-72%. The bivalent prefusion F vaccine, introduced in late 2024, showed remarkable effectiveness when given more than 14 days before delivery. Among RSV-positive hospitalized infants, only 11% had vaccinated mothers compared to 33% of RSV-negative controls. This real-world evidence confirms clinical trial results and validates the UK's maternal vaccination program for protecting vulnerable newborns during their first months of life.
Detailed Summary
Respiratory syncytial virus (RSV) represents the leading cause of severe respiratory infections in infants under 6 months globally, making prevention strategies critical for protecting this vulnerable population. The UK's introduction of maternal RSV vaccination in August-September 2024 provided a unique opportunity to assess real-world vaccine effectiveness.
Researchers conducted a comprehensive test-negative case-control study across 30 UK hospitals, analyzing 537 mother-infant pairs from September 2024 to January 2025. The study included 391 RSV-positive hospitalized infants and 146 RSV-negative controls, with median ages around 1.5 months.
The results were striking: maternal vaccination reduced infant hospitalization risk by 58% overall and 72% when administered more than 14 days before delivery. Only 19% of RSV-positive cases had vaccinated mothers compared to 41% of controls, demonstrating clear protective effects. The vaccine showed particular effectiveness when given with adequate time for maternal antibody transfer.
These findings validate the UK's maternal vaccination strategy and provide crucial real-world evidence supporting RSV prevention programs. The study confirms that clinical trial efficacy translates effectively to routine healthcare settings, offering hope for reducing the substantial burden of RSV-related infant hospitalizations globally.
Key Findings
- Maternal RSV vaccination reduced infant hospitalization risk by 72% when given >14 days before delivery
- Only 19% of hospitalized RSV-positive infants had vaccinated mothers vs 41% of controls
- Real-world effectiveness matched clinical trial results in first implementation season
- Study included 537 mother-infant pairs across 30 UK hospitals over 4 months
Methodology
Multicentre test-negative case-control study across 30 UK hospitals comparing RSV-positive hospitalized infants to RSV-negative controls. Conditional logistic regression adjusted for site, calendar month, age, preterm birth, and sex to calculate vaccine effectiveness.
Study Limitations
Study limited to first season of vaccine implementation with relatively short follow-up period. Observational design cannot establish causation, and effectiveness may vary across different RSV seasons or populations.
Enjoyed this summary?
Get the latest longevity research delivered to your inbox every week.