Real-world data reaffirm RSVpreF vaccine’s benefit in older individuals

Along with its efficacy established in the pivotal RENOIR trial, real-world studies published more recently continue to demonstrate effectiveness of the bivalent respiratory syncytial virus (RSV) prefusion F protein–based (RSVpreF) vaccine in protecting against RSV-associated outcomes in older individuals aged ≥60 years.

RENOIR: Efficacy in older individuals
Available in Hong Kong since 2024, the first and only single-dose, bivalent RSVpreF vaccine demonstrated strong vaccine efficacy (VE) for prevention of lower respiratory tract disease (LRTD) caused by RSV in individuals aged ≥60 years in the pivotal phase III RENOIR trial. [RSVpreF vaccine Hong Kong Prescribing Information; https://www.pfizer.com.hk/en/newsroom-en/pfizer%E2%80%99s-first-dual-indication-vaccine-for-respiratory-syncytial-virus-rsv-is-available-this-month-in-hong-kong; N Engl J Med 2023;388:1465-1477]

The multicentre, double-blind, randomized, placebo-controlled trial, initiated in August 2021, involved 240 study sites in 7 countries, including Argentina, Canada, Finland, Japan, the Netherlands, South Africa, and the US. Participants aged ≥60 years were randomized 1:1 to receive a single intramuscular dose of RSVpreF vaccine 120 μg or placebo. During the first RSV season from August 2021 to October 2022 (n=36,134), RSVpreF vaccine demonstrated a VE of 88.9 percent against RSV-associated LRTD with ≥3 signs or symptoms (95 percent confidence interval [CI], 53.6–98.7). [N Engl J Med 2023;388:1465-1477; MMWR Morb Mortal Wkly Rep 2023;72:793-801]

Real-world effectiveness
Multiple studies conducted during the 2023–2024 RSV season evaluated real-world protection provided by the RSVpreF vaccine in older individuals.

Reduced hospitalization and ED events in high-risk population
A retrospective, observational, test-negative case-control study conducted at Kaiser Permanente Southern California estimated the effectiveness of RSVpreF vaccine in high-risk older individuals by analyzing 5,714 LRTD hospitalizations or emergency department (ED) encounters (median age, 77.4 years; 94.8 percent with ≥1 Charlson comorbidity; 15.1 percent immunocompromised) that occurred between 24 November 2023 and 9 April 2024. [JAMA Netw Open 2024;7:e2450832]

RSVpreF vaccine offered protection against RSV-related LRTD hospitalization, with an estimated adjusted vaccine effectiveness of 90 percent (95 percent CI, 20–99). The vaccination also reduced RSV-related LRTD ED visits, with an estimated adjusted vaccine effectiveness of 89 percent (95 percent CI, 8–99). Similar protection was observed for severe RSV-related LRTD hospitalization and ED events, with an estimated adjusted vaccine effectiveness of 91 percent (95 percent CI, 28–99).

Effectiveness in immunocompetent individuals
In another test-negative study using electronic health records from the Virtual SARS-CoV-2, Influenza, and Other Respiratory Viruses Network (VISION), RSVpreF vaccine’s effectiveness was assessed in individuals aged ≥60 years across 230 hospitals and 245 EDs in 8 US states from October 2023 to March 2024. In older individuals without documented immunocompromise, RSVpreF vaccine demonstrated an estimated effectiveness of 73 percent (95 percent CI, 52–85) against RSV-associated hospitalization and 79 percent (95 percent CI, 59–89) against RSV-associated ED encounters. [Lancet 2024;404:1547-1559]

Effectiveness in a large veteran cohort
A large-scale target trial emulation study, conducted from September to December 2023 using national Veterans Health Administration data, evaluated the effectiveness of a single dose of RSV vaccine (either RSVpreF or RSVPreF3 vaccine) among 146,852 vaccinated veterans aged ≥60 years matched to 582,936 unique controls, weighted equally to represent 146,852 individuals (male, 94.0 percent; median age, 75.9 years; median follow-up, 124 days). The study’s primary outcome was any positive RSV test result occurring from day 14 after vaccination until the end of the study period. [Lancet Inf Dis 2025;25:625-633]

In the RSVpreF vaccine cohort, the incidence rate of documented RSV infections was 2.6 vs 11.1 events per 1,000 person-years in the vaccinated vs unvaccinated group, corresponding to an estimated vaccine effectiveness of 77.4 percent (95 percent CI, 70.4–82.4).

Protection for at-risk populations
These real-world data highlight the RSVpreF vaccine’s benefit in preventing RSV-related outcomes in older individuals, reinforcing its role in protecting at-risk populations during RSV seasons.