We begin with the following key considerations:

- Despite the "emergency brake," the third wave will lead to higher incidences at its peak than the second wave, since mutation B.1.1.7 is significantly more contagious than the previous virus variants. This despite the positive effects of vaccination and warmer weather, which have already been taken into account.

- Nearly all infections in our model are due to unprotected indoor contacts. If the R value is to be kept below 1, additional efforts must be made to reduce such unprotected contacts.

According to the model, infections occur almost entirely in the following areas: own household; private visits; work; school. Infections take place primarily when these contacts are unprotected. We discuss possible measures for the different areas; a quantitative overview of the results is provided in in the Appendix.

We examine the effects of rapid tests. The simulations include many possible combinations; in this report, we focus on "1x/week in education" plus "1x/week at work" plus testing before 20% of reciprocal visits. This results in approximately 3.4 million tests per week for Berlin, and is thus consistent with currently communicated target numbers.

In our mathematical model, we examine the interactions between strategies in different regions. The model shows that regional strategies can only be successful if regions connected by exchanges of people proceed in a coordinated manner.
