Efficacy of vaccination against the Omicron variant of SARS-CoV-2
In December 2021,a new mutant strain of SARS-CoV-2,Omicron,was first reported in South Africa.This variant contains many mutations and exhibits high transmission and immune escape ability,leading to an increased odds of breakthrough infection.As of July 2022,Omicron had become the predominant epidemic strain causing COVID-19.As one of the main means of virus prevention,the efficacy of vaccine against Omicron needs to be evaluated.This review summarizes and compares the immune efficacy of different types and doses of vaccines against Omicron,outlines the effects of homologous and heterologous booster vaccination against Omicron in several trials,and discusses vaccine safety and more optimal vaccination regimens.