Figure 1.

Effective reproduction numbers R_t^Empirical and R_t^Model-based in Qatar. A) Trend in R_t^Empirical and R_t^Model-based, April 1, 2020 to August 18, 2021, and association with major events, response landmarks, and introduction and expansion of the Alpha (B.1.1.7) and Beta (B.1.135) variants. B) Trend in R_t^Empirical for only the Alpha variant cases, February 1, 2021 to April 1, 2021. R_t^Empirical was estimated using the Robert Koch Institute method [23] applied to symptomatic case series data. The dashed green line represents the threshold of R₀ = 1.