Two studies published today measure the vaccine effectiveness (VE) of COVID-19 vaccines against laboratory-confirmed Omicron variant and subvariants and symptomatic disease. Vaccines that target the newer variants performed well, but primary vaccines offered rapidly waning protection from SARS-CoV-2 infections in the post-Omicron era.
Bivalent vaccine 72% protective against Omicron infection
In Open Forum Infectious Diseases, researchers share their case-control study, which measured the effectiveness of bivalent (two-strain) COVID-19 mRNA vaccines against symptomatic infection during the BA.5-dominant period in Japan—September 20 through December 31, 2022. This is one of the first studies to measure VE of newer BA.4/BA.5-containing bivalent vaccines, which were developed in 2022 to target highly transmissible Omicron subvariants. ...
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