Bivalent RSVpreF effectiveness against RSV-related lower respiratory tract disease hospitalization and ED visits across three RSV Seasons

  1. Sara Y. Tartof
  2. Evan J. Zasowski
  3. Negar Aliabadi
  4. Gabriella Goodwin
  5. Jeff Slezak
  6. Vennis Hong
  7. Timothy B. Frankland
  8. Bradley Ackerson
  9. Qing Liu
  10. Sally Shaw
  11. Sabrina Welsh
  12. Banshri Kapadia
  13. Brigitte C Spence
  14. Gregg S. Davis
  15. Joseph A. Lewnard
  16. Hina Chowdhry
  17. Michael Dutro
  18. Erica Chilson
  19. Alejandro Cane
  20. Kyla Hayford
  21. Elizabeth Begier
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Abstract

Introduction

RSV vaccines reduce the risk of severe outcomes such as hospitalization and emergency department (ED) visits for at least 2 RSV seasons following vaccination. No data have been published on real-world RSV vaccine effectiveness (VE) beyond the second season after vaccination. This study evaluates bivalent RSVpreF VE against RSV-related lower respiratory tract disease (LRTD) hospitalizations/ED visits throughout 3 seasons after vaccination.

Methods

This retrospective test-negative case-control evaluates bivalent RSVpreF VE among adults aged ≥60 years at Kaiser Permanente Southern California with LRTD over 3 RSV seasons (11/24/2023–4/18/2026). Cases were RSV-positive without coinfection. Controls were negative for RSV, hMPV, influenza, SARS-CoV-2, and positive for a non-vaccine preventable disease pathogen. Exposure was bivalent RSVpreF (Abrysvo) receipt ≥21 days before LRTD. Adjusted VE was estimated using odds ratios from multivariable logistic regression or generalized estimating equations.

Results

Overall, adjusted VE against RSV-related LRTD hospitalization/ED visits was 80% (95% CI:68–87), 70% (95% CI:53–81), and 51% (95% CI:-12–78) in the first, second, and third season after vaccination, respectively. Among non-immunocompromised individuals, adjusted VE against RSV-related LRTD was 87% (95% CI:75–94), 76% (95% CI:55–87), and 58% (95% CI:-21–86) in the first, second, and third season after vaccination, respectively. Adjusted VE across the 3 combined seasons was 73% (95% CI: 64-80) overall and 80% (95% CI: 69-87) among non-immunocompromised individuals.

Conclusion

These results suggest Bivalent RSVpreF provides protection against RSV-related LRTD outcomes for at least three seasons after vaccination in this population of older adults with a prevalence of comorbidities. This suggests RSV vaccination results in substantial individual and public health benefit.

Key Summary Points

Why carry out this study?

  • RSV vaccines reduce the risk of severe outcomes such as hospitalization and emergency department (ED) visits for at least 2 RSV seasons after vaccination

  • Real-world RSV vaccine effectiveness (VE) beyond the second season after vaccination is currently unknown

  • This study evaluates bivalent RSVpreF VE against RSV-related lower respiratory tract disease (LRTD) hospitalizations/ED visits throughout 3 seasons after vaccination.

What was learned from this study?

  • Overall, VE against RSV-related LRTD hospitalization/ED visits was 80% (95% CI:68–87), 70% (95% CI:53–81), and 51% (95% CI:-12–78) in the first, second, and third season after vaccination, respectively, and 73% (95% CI: 64-80) across the 3 combined seasons.

  • These results suggest Bivalent RSVpreF provides protection against RSV-related LRTD outcomes for at least three seasons after vaccination in this population of older adults with a prevalence of comorbidities.

  • RSV vaccination results in substantial individual and public health benefit.

Article activity feed

  1. Version published to 10.64898/2026.07.08.26357564 on medRxiv