COVID-19 infectivity profile correction

TL;DR

This paper identifies and corrects a mistake in the COVID-19 infectivity profile from a 2020 study, providing an accurate profile crucial for policy and research decisions.

Contribution

It corrects the infectivity profile of COVID-19 from a key study, establishes confidence intervals, and discusses normalization issues affecting serial interval data fitting.

Findings

Corrected infectivity profile for COVID-19

Quantified differences between original and corrected profiles

Discussed normalization issues in serial interval data

Abstract

The infectivity profile of an individual with COVID-19 is attributed to the paper Temporal dynamics in viral shedding and transmissibility of COVID-19 by He et al., published in Nature Medicine in April 2020. However, the analysis within this paper contains a mistake such that the published infectivity profile is incorrect and the conclusion that infectiousness begins 2.3 days before symptom onset is no longer supported. In this document we discuss the error and compute the correct infectivity profile. We also establish confidence intervals on this profile, quantify the difference between the published and the corrected profiles, and discuss an issue of normalisation when fitting serial interval data. This infectivity profile plays a central role in policy and decision making, thus it is crucial that this issue is corrected with the utmost urgency to prevent the propagation of this error into further studies and policies. We hope that this preprint will reach all researchers and policy makers who are using the incorrect infectivity profile to inform their work.