Bivalent COVID vaccines: how they're stacking up against omicron
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A large study from the US Centers for Disease Control and Prevention looked at adults with symptomatic COVID between September and November 2022. It found that use of a bivalent booster targeting the original virus plus the omicron BA.4/BA.5 variant provided additional protection against symptomatic infection compared with a monovalent booster targeting just the original strain.
Other US studies have shown the risk of hospitalization was reduced by at least 38% in people who received a bivalent booster compared to those who had received two or more doses of the original vaccines. In adults over 65 the additional protection was as high as 73%.
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