Assessing the Potential Public Health Impact of the mRNA-Based Respiratory Syncytial Virus (RSV) Vaccine, mRNA-1345, With a Broad Vaccination Campaign Among Older Adults in the United Kingdom: Modelling Study

OBJECTIVES: RSV is a significant cause of lower respiratory tract disease (LRTD) in older adults in the UK, leading to substantial morbidity, mortality, and economic disruption. The Joint Committee on Vaccination and Immunisation advised to provide vaccination against RSV for adults aged 75-80 years as a one-off campaign, and then vaccinating those turning 75 years in subsequent years. This study aims to estimate the public health impact of a broader vaccination campaign among adults aged ≥60 years using mRNA-1345 RSV vaccine over a twenty-year time horizon.

METHODS: An age-stratified dynamic transmission model was used to estimate the impact of vaccination with mRNA-1345 in the UK, projecting the number of incident RSV infections, associated hospitalisations, and deaths averted over twenty-years compared to no vaccination. Model inputs were obtained using published UK specific literature, when available, and phase 2/3 clinical trial data (median follow up of 18.8-months). The model was calibrated to reproduce the expected number of RSV-related hospitalisations in the UK, informed by surveillance reports for 2023/2024 season. Two vaccination strategies with mRNA-1345 were assessed, targeting individuals aged ≥60 or ≥65 years, with 80% coverage and biennial vaccination.

RESULTS: Compared to no vaccination, vaccinating adults aged ≥60 years over twenty-years could prevent more than 25,000,000 RSV infections (symptomatic and asymptomatic), 169,000 hospitalisations and 93,000 of deaths in the targeted population. Restricting vaccination to adults aged ≥65 years, would still have a considerable impact, averting more than 17,000,000 RSV infections, 153,000 of hospitalisations and 89,000 of deaths.

CONCLUSIONS: A broad mRNA-1345 vaccination campaign against RSV targeting older adults aged ≥60 in the UK could substantially reduce the number of RSV infections, associated hospitalisations and deaths. Efforts to improve vaccine access are essential to ensure a substantial long-term decrease in the burden of RSV on individuals and the healthcare system.