Figure 1.

Examples of time series analyses performed on the temporal incidence of SARS-CoV-2 infections (grey area, left scale) and the incidence of COVID-19 associated deaths (red line, right scale). The three-phase-prediction model (black line, right scale) for COVID-19 associated deaths based on actual incidences has been estimated for each country. The second phase of the model with a constant number of deaths is identifiable by the horizontal black line. (a) Greece (cluster 1), exhibits a constant increase of incidences over time (${\alpha }_1=4.7\%$ and ${\alpha }_2=4.2\%$). (b) For Germany (${\alpha }_1=4.5\%$ and ${\alpha }_2=1.5\%$—cluster 2), and (c) the Netherlands (${\alpha }_1=13.1\%$ and ${\alpha }_2=0.8\%$—cluster 3), the threshold effect is particularly visible: the case fatality rates did not increase during the summer months, despite a relevant increase of COVID-19 incidences.