Fig. 9From: The optimal vaccination strategy to control COVID-19: a modeling study in Wuhan City, ChinaThe interaction of transmissibility between different age groups in four stages of Wuhan City. A Stage 1: December 2, 2019, to January 23, 2020. B Stage 2: January 24 to February 2, 2020. C Stage 3: February 3 to February 18, 2020. D Stage 4: February 19, 2020, to March 16, 2020Back to article page