Bivalent mRNA-1273.214 vaccine effectiveness against SARS-CoV-2 omicron XBB* infections

J Travel Med. 2023 Sep 5;30(5):taad106. doi: 10.1093/jtm/taad106.


Effectiveness of the 50-μg mRNA-1273.214 bivalent vaccine against SARS-CoV-2 infection was modest at 25% in a matched, retrospective, cohort study in Qatar comparing infection incidence in the bivalent cohort to that in the national no-recent-vaccination resident cohort. XBB* immune evasion, immune imprinting effects, or both, may explain findings.

Keywords: Hybrid immunity; Qatar; asymptomatic infection; natural infection; variant-containing COVID-19 vaccines; waning vaccine effectiveness.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • COVID-19*
  • Humans
  • SARS-CoV-2
  • Vaccine Efficacy


  • mRNA-1273.214 COVID-19 vaccine