RSV maternal vaccine cuts baby hospital admissions by up to 85%
The introduction of respiratory syncytial virus (RSV) vaccination for pregnant mothers has dramatically reduced the risk of hospitalisations for the illness in babies, real-world data shows.
A study tracking almost 300,000 infants in England in 2024/25 has found babies born to vaccinated mothers were up to 85% less likely to be hospitalised with RSV.
The UK Health Security Agency (UKHSA) research also found high protection for preterm babies when there is a two-week interval between vaccination and birth.
More than 4,500 hospitalisations for RSV occurred in newborn babies in the cohort, the vast majority in infants whose mothers had not been vaccinated, UKHSA said.
Babies born at least four weeks after their mother was vaccinated had nearly 85% protection, reinforcing the advice to be vaccinated in week 28 of pregnancy.
But even vaccination as close as 10 to 13 days before birth reduced hospital admissions by 50%, the data showed.
Vaccine effectiveness was estimated at 69.4% in preterm infants, when allowing at least 14 days between vaccination and birth, the results showed.
The study – the largest dataset so far – was presented at the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) global conference.
Matt Wilson, lead author and an epidemiologist at UKHSA, said: ’Our evaluation of the first season of the programme in England gives important confirmation that maternal RSV vaccination is highly protective for newborn infants, over 80%, and that effectiveness reached nearly 85% when vaccination occurred at least four weeks before birth.
‘These findings are also particularly important for preterm infants, who are among the most vulnerable to severe RSV infection.’
Maternal RSV vaccine uptake in England was 55% during the study period and has since risen to 64.1% for women who gave birth in November 2025.
Dr Conall Watson, consultant epidemiologist at UKHSA, co-author and national programme lead for RSV, said:
‘Half of newborns will have caught RSV before they are a year old. As an expectant parent you have no idea if they are going to be severely ill or not.
‘Our analysis of the RSV vaccination programme in England is important confirmation of the results from the clinical trial, but this study is 40 times bigger and clearly shows the hugely beneficial effect on reducing hospital admission.’
Previously a real-world analysis of RSV vaccination in older people had shown it was 82% effective against hospitalisation.
Both maternal and older people vaccination were introduced in September 2024.
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