Coronavirus disease 2019 scenarios for a long-term strategy under fundamental uncertainty

Early on, scientists have pointed out that coronavirus disease 2019 is most likely here to stay, although its course and development are uncertain. This requires a long-term strategy of living with the virus. However, the urgency of new waves of infection and the emergence of new variants have invoked an approach of acute crisis management over and over, hindering the design of a structural approach for the long term. Exploratory scenarios can provide scientific strategic guidance to policy processes to be better prepared in this situation of fundamental uncertainty. We have therefore developed five scenarios, which describe the possible long-term development of the pandemic from an epidemiological, virological, and broader societal perspective. These scenarios are based on four driving forces that are both important and uncertain: immunity, vaccination, mutations, and human behavior. The scenarios are (1) return to normal, (2) flu+, (3) external threat, (4) continuous struggle, and (5) worst case. Working with scenarios is crucial for appropriate public communication and provides guidance for anticipating the various conceivable possibilities for the further course of the pandemic.