Figure 2.

SARS-CoV-2 incubation period by variant responsible for infection, observed and corrected for day 5 to day 9 of incubation

Estimation obtained from 20 413 COVID-19 cases included in the ComCor case-control study between October, 2020, and February, 2022, with an identified incubation period and variant. Gamma distribution parameters and probabilities of rounding to the nearest week (ie, 7 days) if the incubation period was 6 days or 8 days (probability p₁) or 5 days or 9 days (probability p₂) were jointly estimated by fitting the model to data with a Monte Carlo Markov Chains algorithm. Probabilities p₁ and p₂ were applied to establish corrected distributions. The included variants are alpha (B.1.1.7), beta (B.1.351), gamma (P.1), delta (B.1.617.2), and omicron (B.1.1.529).