Abstract
BACKGROUND: The United Kingdom (UK) introduced RSVpreF vaccine into its national immunization program for persons 75 years of age (with catch up for those 76–79 years) in 2024, first in Scotland (August), then in England (September). We evaluated how the UK’s published population-level reductions in RSV-related hospitalizations correspond to previously reported vaccine effectiveness (VE) from real-world VE studies. [Figure: see text] [Figure: see text] METHODS: We identified available estimates for RSVpreF VE and population-level impact data. Using the formula impact=VE*uptake, we graphed expected vaccine impact across all potential vaccine coverage values based on available VE data against RSV-related hospitalization and published impact results. We also estimated VE based on published impact results. RESULTS: In Scotland and England, RSV-related hospitalizations decreased 62% and 30–34%, respectively, based on regression discontinuity methods. We identified three real-world RSVpreF-specific VE estimates against RSV-related hospitalizations (all from US): 73% (CDC VISION), 85% (FDA Medicare), and 91% (Kaiser Permanente Southern California). Several factors likely contributed to variability in these VEs (e.g., duration of post-vaccination follow-up, use of specimen salvage, vaccine exposure data quality, and outcome definitions). Impact measured in the UK closely aligned with expected results estimated from VE studies (Figure). VEs calculated from impact estimates varied: 91% [Scotland] to 72–76% [England] (Table). Stability in vaccine coverage across evaluation periods may contribute to this variability; Scotland’s coverage was ∼69% throughout, while England’s rose from 35–47%. CONCLUSION: Early impact results from UK’s RSVpreF vaccination program among adults aged 75–79 are consistent with previously reported VE results from the US. The initial public health impact of this vaccination program in preventing RSV-related hospitalizations is already substantial and could increase with higher vaccine uptake, expansion to other at-risk populations, and inclusion of the expected multiple seasons of protection from vaccination. Protection of older adults from severe RSV disease is off to a promising start. DISCLOSURES: Negar Aliabadi, MD, MS, Pfizer: i am an employee|Pfizer: Stocks/Bonds (Public Company) Qing Liu, M.S., Pfizer Inc.: I am Pfizer employee and hold Pfizer stocks|Pfizer Inc.: Stocks/Bonds (Public Company) Carmen Hockey, MBChB MSc, Pfizer Ltd: Stocks/Bonds (Private Company) Andrew Vyse, Ph.D., Pfizer UK Ltd: Ownership Interest|Pfizer UK Ltd: Stocks/Bonds (Private Company) Gillian Ellsbury, MD, Pfizer Ltd: Stocks/Bonds (Public Company) Luis Jodar, PhD, Pfizer Inc: Stocks/Bonds (Public Company) Elizabeth Begier, MD, M.P.H., Pfizer: I am an employee.|Pfizer: Stocks/Bonds (Public Company)