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# Positive Results in Pfizer RSV Vaccine Trial
- URL: https://www.fdaweb.com/positive-results-in-pfizer-rsv-vaccine-trial/
- Published: 2022-08-25T12:00:00.000Z
- Updated: 2026-09-14T17:57:20.000Z
- Author: David McFarland
- Tags: Biologics, #legacy-id-D5152593

Pfizer says results from a Phase 3 trial of older adults for its respiratory syncytial virus (RSV) prefusion F vaccine candidate showed efficacy of 85.7% in participants with more severe disease primary endpoint of lower respiratory tract illness. A company [statement](https://www.pfizer.com/news/press-release/press-release-detail/pfizer-announces-positive-top-line-data-phase-3-trial-older?ref=fdaweb.com) says the vaccine was well-tolerated with no safety concerns. As a result, Pfizer says, it will seek regulatory approval this fall.