Fig. 5From: The effect of a strict facial-mask policy on the spread of COVID-19 in Switzerland during the early phase of the pandemicEvolution of the strict facial-mask policy during the second half of 2020: A value of 0 corresponds to the government-determined baseline policy while a value of 1 indicates a strict facial-mask policy as described in Sect. 2.2. The red line denotes the government-determined baseline policyBack to article page