The serial interval of COVID-19 from publicly reported confirmed cases


As a novel coronavirus (COVID-19) continues to emerge throughout China and threaten the globe, its transmission characteristics remain uncertain. Here, we analyze the serial intervals-the time period between the onset of symptoms in an index (infector) case and the onset of symptoms in a secondary (infectee) case-of 468 infector-infectee pairs with confirmed COVID-19 cases reported by health departments in 18 Chinese provinces between January 21, 2020, and February 8, 2020. The reported serial intervals range from -11 days to 20 days, with a mean of 3.96 days (95% confidence interval: 3.53-4.39), a standard deviation of 4.75 days (95% confidence interval: 4.46-5.07), and 12.1% of reports indicating pre-symptomatic transmission. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement We acknowledge the financial support from NIH (U01 GM087719) and the National Natural Science Foundation of China (61773091). ### Author Declarations All relevant ethical guidelines have been followed; any necessary IRB and/or ethics committee approvals have been obtained and details of the IRB/oversight body are included in the manuscript. Yes All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All data used in this study is from open access.

MIDAS Network Members


Du Zhanwei, Wang Lin, Xu Xiaoke, Wu Ye, Cowling Benjamin J, Meyers Lauren Ancel. (2020). The serial interval of COVID-19 from publicly reported confirmed cases. Cold Spring Harbor Laboratory Press