Influenza vaccination in italian healthcare workers (2018–2019 season): Strengths and weaknesses. results of a cohort study in two large italian hospitals

CIRI-IT Team, Donatella Panatto, Piero Luigi Lai, Stefano Mosca, Elvina Lecini, Andrea Orsi, Alessio Signori, Silvana Castaldi, Elena Pariani, Laura Pellegrinelli, Cristina Galli, Giovanni Anselmi, Giancarlo Icardi

Research output: Contribution to journalArticle

Abstract

Background: Annual vaccination is the most effective way to combat influenza. As influenza viruses evolve, seasonal vaccines are updated annually. Within the European project Development of Robust and Innovative Vaccine Effectiveness (DRIVE), a cohort study involving Italian healthcare workers (HCWs) was carried out during the 2018-2019 season. Two aims were defined: to measure influenza vaccine effectiveness (IVE) against laboratory-confirmed influenza cases and to conduct an awareness-raising campaign to increase vaccination coverage. Methods: Each subject enrolled was followed up from enrollment to the end of the study. Each HCW who developed ILI was swabbed for laboratory confirmation of influenza. Influenza viruses were identified by molecular assays. A Cox regression analysis, crude and adjusted for confounding variables, was performed to estimate the IVE. Results: Among the 4483 HCWs enrolled, vaccination coverage was 32.5%, and 308 ILI cases were collected: 23.4% were positive for influenza (54.2% A(H1N1) pdm09; 45.8% A(H3N2)). No influenza B viruses were detected. No overall IVE was observed. Analyzing the subtypes of influenza A viruses, the IVE was estimated as 45% (95% CI:-59 to 81) for A(H1N1) pdm09. Conclusions: Vaccination coverage among HCWs increased. Study difficulties and the circulation of drifted variants of A(H3N2) could partly explain the observed IVE.

Original languageEnglish
Article number119
JournalVaccines
Volume8
Issue number1
DOIs
Publication statusPublished - Mar 2020

Keywords

  • Healthcare workers
  • Influenza
  • Influenza vaccination
  • Influenza vaccination coverage
  • Laboratory-confirmed influenza

ASJC Scopus subject areas

  • Immunology
  • Pharmacology
  • Drug Discovery
  • Infectious Diseases
  • Pharmacology (medical)

Fingerprint Dive into the research topics of 'Influenza vaccination in italian healthcare workers (2018–2019 season): Strengths and weaknesses. results of a cohort study in two large italian hospitals'. Together they form a unique fingerprint.

  • Cite this

    CIRI-IT Team, Panatto, D., Lai, P. L., Mosca, S., Lecini, E., Orsi, A., Signori, A., Castaldi, S., Pariani, E., Pellegrinelli, L., Galli, C., Anselmi, G., & Icardi, G. (2020). Influenza vaccination in italian healthcare workers (2018–2019 season): Strengths and weaknesses. results of a cohort study in two large italian hospitals. Vaccines, 8(1), [119]. https://doi.org/10.3390/vaccines8010119