Quite different from F ′ (x), F ′′ (x) removed the time trend of F ′ (x) to show the acceleration/deceleration of diagnosed COVID-19. Consequently, F ′  ′ (x) was much more sensitive than F ′ (x) to gauge the intrinsic dynamics of the epidemic in response to the massive anti-COVID-19 action. Since January 21, 2020 after the massive anti-COVID actions, the F ′  ′ (x) suddenly became very active, as indicated by the alternative accelerations and decelerations. F ′  ′ (x) reached the peak on January 27 after the distribution of large number of test kits on January 26, which was an action based on the decision at the central government level in a meeting held by Chinese President Xi Jinping on January 24 and 25, the Chinese New Year’s Eve and New Year’s Day.