ESCMID 2026
Real world evidence links maternal RSV vaccination to fewer infant hospitalizations
Clinical takeaway: For pregnant patients, RSV vaccination early in the third trimester (starting at 28 weeks gestation) should be strongly encouraged—especially when preterm delivery is possible—as vaccination ≥2 weeks before birth reduces infant RSV hospitalizations by ~80%, with even greater protection when given earlier.
Respiratory syncytial virus (RSV) remains a leading cause of hospitalization in infants worldwide, with the highest risk in the first months of life. New data presented at ESCMID Global 2026 in Munich provide some of the strongest real‑world evidence to date that maternal RSV vaccination can meaningfully reduce this burden.
In the largest observational analysis so far, UK investigators evaluated 289,399 infants born in England between September 2024 and March 2025 following rollout of a national maternal RSV vaccination program. Across the cohort, 4,594 RSV‑associated hospitalizations were identified. Although infants born to unvaccinated mothers represented 55% of births, they accounted for 87.2% of hospitalizations.
By contrast, infants whose mothers were vaccinated ≥14 days before delivery had an 81.3% lower risk of RSV‑related hospitalization. Protection increased with earlier vaccination, approaching ~85% effectiveness when vaccination occurred ≥4 weeks before birth. Even among preterm infants, vaccine effectiveness was estimated at 69.4% with at least a two‑week interval.
“As the largest study to date examining the impact of this vaccine on infant hospitalization, these findings provide robust evidence that maternal vaccination offers substantial protection against severe RSV disease,” said Matt Wilson, PhD, epidemiologist at the UK Health Security Agency.
Source: ESCMID press release/EurekAlert. (2026, April 17). Maternal RSV vaccination cuts infant hospitalization risk by over 80%, major UKHSA study finds