R(t) was calculated using the EpiEstim package, developed by Cori et al. (2013; DOI: 10.1093/aje/kwt133), in the R software environment. Case recorded date was used as the time anchor, except for the Ontario R(t) value. Estimate of R(t) uses a 7-day window, and a Generation Time consistent with current literature (mean 3.5, SD 3.3). I use case data sourced from JP Soucy and Isha Berry (2021, https://github.com/ccodwg/Covid19Canada).