Influenza Vaccine Effectiveness Against Illness and Asymptomatic Infection in 2022-2023: a Prospective Cohort Study.

Details

• Alternative Title:
  Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America, 2025, v. 80, no. 4: Influenza Vaccine Effectiveness Against Illness and Asymptomatic Infection in 2022-2023: a Prospective Cohort Study.
• Journal Article:
  Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America
• Personal Author:
  White, Elizabeth B. ; Grant, Lauren ; Mak, Josephine ; Olsho, Lauren ; Edwards, Laura J. ; Naleway, Allison ; Burgess, Jefferey L. ; Ellingson, Katherine D. ; Tyner, Harmony ; Gaglani, Manjusha ; Lutrick, Karen ; Caban-Martinez, Alberto ; Newes-Adeyi, Gabriella ; Duque, Jazmin ; Yoon, Sarang K. ; Phillips, Andrew L. ; Thompson, Mark ; Britton, Amadea ; Flannery, Brendan ; Fowlkes, Ashley
• Description:
  Previous estimates of vaccine effectiveness (VE) against asymptomatic influenza virus infection based on seroconversion have varied widely and may be biased. We estimated 2022-2023 influenza VE against illness and asymptomatic infection in a prospective cohort.
  
  In the HEROES-RECOVER cohort, adults at increased occupational risk of influenza exposure across 7 US sites provided weekly symptom reports and nasal swabs for reverse transcription-polymerase chain reaction (RT-PCR) influenza testing. Laboratory-confirmed influenza virus infections were classified as symptomatic (≥1 symptom) or asymptomatic during the week of testing. Participants reported demographic information and vaccination through surveys; most sites verified vaccination through medical record and immunization registry review. Person-time was calculated as days from the site-specific influenza season start (September-October 2022) through date of infection, study withdrawal, or season end (May 2023). We compared influenza incidence among vaccinated versus unvaccinated participants overall, by symptom status, and by influenza A subtype, using Cox proportional hazards regression adjusted for site and occupation. We estimated VE as (1 - adjusted hazard ratio) × 100%.
  
  In total, 269 of 3785 (7.1%) participants had laboratory-confirmed influenza, including 263 (98%) influenza A virus infections and 201 (75%) symptomatic illnesses. Incidence of laboratory-confirmed influenza illness among vaccinated versus unvaccinated participants was 23.7 and 33.2 episodes per 100 000 person-days, respectively (VE: 38%; 95% CI: 15%-55%). Incidence of asymptomatic influenza virus infection was 8.0 versus 11.6 per 100 000 (VE: 13%; 95% CI: -47%, 49%).
  
  Vaccination reduced incidence of symptomatic but not asymptomatic influenza virus infection, suggesting that influenza vaccination attenuates progression from infection to illness.
• Content Notes:
  Author manuscript
• Subjects:
  • Humans
  • Influenza, Human
  • Influenza Vaccines
  • Prospective Studies
  • Male
  • Female
  • Middle Aged
  • Adult
  • Asymptomatic Infections
  • Vaccine Efficacy
  More +
• Keywords:
  • influenza
  • vaccines
  • cohort
  • asymptomatic infection
  • symptomatic illness
• Source:
  Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America, 2025, v. 80, no. 4
• DOI:
  https://doi.org/10.1093/cid/ciae491
• ISSN:
  1058-4838 ; 1537-6591
• Pubmed ID:
  39446477
• Pubmed Central ID:
  PMC13289553
• Document Type:
  Text
• Funding:
  IP/NCIRD CDC HHSUnited States/ ; CC/CDC HHSUnited States/ ; Marshfield Clinic Research Institute/ ; University of Arizona/ ; Abt Associates/ ; IP/NCIRD CDC HHSUnited States/ ; CC/CDC HHSUnited States/
• Genre:
  Journal Article
• Place as Subject:
  United States
• Pages in Document:
  893-900 (15 pdf pages)
• Volume:
  80
• Issue:
  4
• Download URL:
  https://stacks.cdc.gov/view/cdc/261955/cdc_261955_DS1.pdf
• File Type:
  [PDF - 277.27 KB]
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha-512:b8cc298151d0835e8b08616e1b837180a0600a3b5bc7dcea6c72b053ea7f668b715b708fbce80d8118943ee30cf5152b561cd8b250c9044ecc555f805e2a978c