Incubation period is an important parameter to inform quarantine period and to study transmission dynamics of infectious diseases. In this article the authors conducted a systematic review and meta-analysis on published estimates of the incubation period distribution of COVID-19, and showed that the pooled median of the point estimates of the mean, median and 95th percentile for incubation period are 6.3 days (range: 1.8 to 11.9 days), 5.4 days (range: 2.0 to 17.9 days) and 13.1 days (range: 3.2 to 17.8 days) respectively. Estimates of the mean and 95th percentile of the incubation period distribution were considerably shorter before the epidemic peak in China compared to after the peak, and variation was also noticed for different choices of methodological approach in estimation. The authors concluded that their findings implied that corrections may be needed before directly applying estimates of incubation period into control of or further studies on emerging infectious diseases.
Hualei Xin, Jessica Y Wong, Caitriona Murphy, Amy Yeung, Sheikh Taslim Ali, Peng Wu, Benjamin J Cowling, The incubation period distribution of coronavirus disease 2019 (COVID-19): a systematic review and meta-analysis, Clinical Infectious Diseases, 2021;, ciab501, https://doi.org/10.1093/cid/ciab501