Research of Epidemiologic Feature and Control of SARS-CoV-2 Omicron Subvariants BA.4 and BA.5

The global COVID-19 is still in a pandemic state, and Omicron is still the dominant variant in the world, accounting for about 99% of the global gene sequence. Many regions around the world are experiencing the seventh wave of the epidemic. This round of epidemics is mainly caused by Omicron subvariants BA.4 and BA.5, but the epidemiological characteristics of Omicron subvariants BA.4 and BA.5 are still unclear, bringing great challenges to the prevention and control of the epidemic in countries and regions. In this study, discovery and epidemic status, the incubation period, transmissibility, clinical symptoms, case fatality rate, and the protective effect of vaccines of Omicron subvariants BA.4 and BA.5 were reviewed, in order to provide reference for scientific prevention and control of Omicron subvariants BA.4 and BA.5.