The Incubation Period of COVID-19 Caused by Different SARS-CoV-2 Variants

ABSTRACT

Since the beginning of the COVID-19 epidemic, the pathogen of COVID-19, SARS-CoV-2, has evolved and mutated continuously, producing variants with different enhanced transmission and virulence, such as Alpha (B.1.1.7), Beta(B.1.351), Gamma(P.1), Delta (B.1.617.2) and Omicron(B.1.1.529). An intensive study of the incubation period of COVID-19 caused by different SARS-CoV-2 variants will contribute to tracing the origin of COVID-19, determining the detention, quarantine and isolation time of close contacts, and timely improving measures for containing COVID-19. We reviewed the major studies on the incubation period of COVID-19 caused by wild-type strains and different variants of SARS-CoV-2, which estimated that the incubation period of COVID-19 caused by wild-type SARS-CoV-2 strains was 4-8(median 5.5) days. And that for COVID-19 caused by Beta or Gamma variant was generally similar to that by wild-type strains, about 5 days. The incubation period of COVID-19 caused by Alpha, Delta and Omicron variants was shorter than that of other strains, which was 4, 4 and 3 days, respectively. Copyright © 2022 by the Chinese General Practice.