The maternal respiratory syncytial virus (RSV) vaccine provides “over 80% protections for newborn infants, including those born prematurely”, for women vaccinated “at least two weeks before birth”, a new UKHSA study has revealed.
Published on April 17, the study found that it “was best” to get the vaccine on time – in week 28 or soon after that – as babies born “at least four weeks after their mother was vaccinated had nearly 85% protection”.
Read more: JCVI: Extend RSV jab to over-65s with chronic respiratory disease
It noted, however, that even vaccination later in pregnancy “still gives some protection, with vaccination as close as 10 to 13 days before birth reducing hospital admissions by 50%”.
And it also found that premature babies can be “well protected” from RSV, provided there are at least two weeks between vaccination and birth.
“There is high confidence in the protective effect of the vaccine,” UKHSA said.
“Hugely beneficial”
The study – believed to be “the largest study in the world evaluating the effect of maternal RSV vaccination in preventing infants from being hospitalised” with the virus – analysed data from 2024/25, the first year of the vaccine’s rollout to pregnant women.
It followed nearly 300,000 babies born between September 2024 and March 2025, “representing around 90% of all births in England during this period”, UKHSA said.
And it noted that maternal RSV vaccine uptake in England “continues to climb”, with the latest data showing uptake “rising to 64.1% for women who gave birth in November 2025”.
Read more: Govt accepts advice to expand RSV vaccine eligibility
UKHSA epidemiologist and lead author of the study Matt Wilson said it “gives important confirmation that maternal RSV vaccination is highly protective for newborn infants”.
He noted that the findings are also “particularly important for preterm infants, who are among the most vulnerable to severe RSV infections”, adding that it is “important that midwives and other healthcare workers offer vaccination on time with the schedule – and that pregnant women promptly take it up”.
Read more: NHSE national RSV campaign points patients to pharmacies
UKHSA consultant epidemiologist and study co-author Dr Conall Watson said the analysis is “important confirmation of the results from the clinical trial” of the vaccine – but is also “40 times bigger and clearly shows the hugely beneficial effect on reducing hospital admission”.
It comes after the Joint Committee on Vaccination and Immunisation (JCVI) advised earlier this month that adults aged 65 to 74 with chronic respiratory disease should be offered the RSV vaccine.
And it follows an UKHSA review of the RSV vaccine pilot in community pharmacies concluding that “current evidence does not show” the model improves “overall vaccine coverage”.
