Figure 9 : COVID-19 China (red lines), Italy (blue lines), the UK (green lines) and South Korea (black lines).

Concavity (i.e. the second derivative) of the observed cases, averaged over a centred 3-day interval.

Roberto Buizza Journal of Medical Statistics and Informatics  2020 8:4DOI : 10.7243/2053-7662-8-4