Fast Five Quiz: COVID-19 Prevention

Michael Stuart Bronze, MD


December 16, 2022

An Israeli study showed a significant reduction in hospitalizations and deaths caused by the Omicron variant with a second booster in adults aged ≥ 60 years. Another Israeli study showed that rates of confirmed SARS-CoV-2 infection and severe COVID-19 were lower after a fourth dose of BNT162b2 vaccine than after three doses. Although protection against confirmed infection was not long-lasting, protection against severe illness was maintained throughout the study period.

Postvaccination, immunity typically wanes after a period of 6 months, making a booster vaccine critical. While vaccination remains effective at preventing severe disease, this protection also wanes over time, and improved immune evasion by the Omicron variant significantly reduces protection against transmission. In addition, acquired immunity seems to be less protective against Omicron variants of COVID-19.

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