Mobility decreased significantly over the Christmas vacations in both Berlin and Cologne. In January, time spent away from home increased again; however, the current level is still below the pre-holiday level (see section 2, p. 1).

The omicron variant is now known to be dominant in most states, and results in sharply increasing incidences, initially often doubling per week. The protective measures still in place, along with with the numerous boosters not far behind, are preventing an even more rapid increase (see Section 3, p. 2).

Our simulations show that voluntary behavioral changes on the part of the population which go beyond the formally ordered measures would make significant contributions to flattening the wave. This applies in particular to those groups of people who are currently exempt from many measures, i.e. in particular also boosted individuals (see Section 4, p. 3).
