Risk and protective factors for SARS-CoV-2 reinfections, surveillance data, Italy, August 2021 to March 2022

Euro Surveill. 2022 May;27(20):2200372. doi: 10.2807/1560-7917.ES.2022.27.20.2200372.

Abstract

We explored the risk factors associated with SARS-CoV-2 reinfections in Italy between August 2021 and March 2022. Regardless of the prevalent virus variant, being unvaccinated was the most relevant risk factor for reinfection. The risk of reinfection increased almost 18-fold following emergence of the Omicron variant compared with Delta. A severe first SARS-CoV-2 infection and age over 60 years were significant risk factors for severe reinfection.

Keywords: Italy; Omicron variant; SARS-CoV-2 reinfections; risk factors; severe disease.

MeSH terms

  • COVID-19*
  • Humans
  • Italy / epidemiology
  • Middle Aged
  • Protective Factors
  • Reinfection
  • SARS-CoV-2*

Supplementary concepts

  • SARS-CoV-2 variants