Bivalent RSV prefusion vaccine effectiveness against hospitalisation in older adults: meta-analysis of case-control studies in England, Wales, Scotland, and Northern Ireland.

BACKGROUND

Respiratory syncytial virus (RSV) causes substantial morbidity and mortality in older adults. In 2023, the RSVpreF vaccine was licenced and recommended for adults through the UK's national immunisation programmes. Real-world evidence on vaccine effectiveness (VE) across different populations and healthcare settings is limited.

METHODS

We conducted a retrospective, multi-nation, test-negative design analysis to evaluate RSVpreF VE against hospitalisation in adults aged 74-79 years across England, Wales, Scotland, and Northern Ireland during the 2024-25 RSV season. Laboratory testing, admission, and vaccination data were linked at the individual patient level. Eligible cases were hospitalised individuals with laboratory-confirmed RSV, and controls were RSV-negative hospitalised patients; SARS-CoV-2- and influenza-positive controls were excluded in the primary analysis. Nation-specific VE estimates were derived using multivariable logistic regression, adjusted for epidemiological week of specimen collection, and combined using fixed-effects meta-analysis with inverse-variance weighting. Sensitivity analyses included redefinition of controls and leave-one-nation-out analyses.

FINDINGS: A total of 11,117 adults were included (6528 in England, 942 in NI, 1462 in Scotland, 2185 in Wales). Overall, 3896 (35.0%) had received RSVpreF. Across nations, 826 RSV-positive cases were identified, of whom 726 (87.9%) were unvaccinated. Adjusted VE against RSV-related hospitalisation was 74% (95% confidence interval [CI] 68-80) in England, 77% (30-95) in NI, 81% (60-91) in Scotland, and 82% (43-94) in Wales. Pooled fixed-effects VE was 75% (69-80; I 2 = 0%). VE estimates from sensitivity analyses were robust to the inclusion of vaccine-preventable respiratory infection controls and adjustment for vaccination status. Leave-one-nation-out sensitivity analysis showed that excluding England increased pooled VE to 81% (66-89), whereas exclusion of NI, Scotland, or Wales had minimal impact (75%, 68-80 to 69-80).

INTERPRETATION: RSVpreF vaccination provides high real-world protection against RSV-related hospitalisation in adults across the UK.

FUNDING: This study received no specific funding.