August 30, 2026NEJM Evidence
Durability of RSV Prefusion F Vaccine Protection across Two RSV Seasons
Authors
Discussion
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Implication
Randomized trial demonstrates durable protection against RSV hospitalization in older adults across two seasons, indicating waning yet persistent vaccine effectiveness.
Key Points
- To evaluate the durability of protection against RSV-related respiratory tract disease hospitalization across two consecutive RSV seasons following a single dose of the bivalent RSV prefusion F vaccine.
- Pragmatic, open-label, randomized trial (ClinicalTrials.gov NCT06684743) assigning adults 60 years of age or older in a 1:1 ratio to receive a single dose of RSVpreF vaccine or no vaccine during the 2024–2025 winter season.
- A total of 131,379 participants were randomly assigned, with 130,991 included in the intention-to-treat population followed through the 2025–2026 winter season to evaluate primary RSV-related respiratory tract disease (RTD) hospitalizations.
- In the second season, RSV-related RTD hospitalization incidence was 0.11 events per 1000 person-years with RSVpreF versus 0.25 events per 1000 person-years in controls, yielding a vaccine effectiveness of 56.2% (95% CI, -12.4% to 84.8%), compared to 83.3% (95% CI, 42.9% to 96.9%) in season one.
- Across both consecutive seasons, the cumulative incidence rate of RSV-related RTD hospitalization was 0.11 versus 0.37 events per 1000 person-years in the RSVpreF and control groups, respectively, representing an overall vaccine effectiveness of 70.6% (95% CI, 39.1% to 87.0%).
- During the second season, no apparent differences were observed between vaccinated and unvaccinated groups for secondary endpoints of all-cause respiratory or cardiorespiratory hospitalizations.
Coverage & sources
Journal, society, and media accounts. Useful signal, not independent expert judgment.
Cite This Study
Lassen et al. (2026) studied this question.