Predictions for the COVID-19 pandemic in Germany using the modified Bateman SIZ model.

AIMS OF THE STUDY: To obtain predictions for the course of the COVID-19 pandemic in Germany using the modified Bateman SIZ model and input variables based on the status quo in July 2020. To predict the effect of a change in tα on the course of the pandemic. To evaluate the robustness and sensitivity of the model in response to a change in the input parameters. MATERIALS AND METHODS: Start parameters for the modified Bateman SIZ model were obtained from observational data published by the Robert-Koch-Institute in Berlin for the period June 1 to July 13, 2020. The robustness and sensitivity of the model were determined by changing the input parameter for the doubling-time (tα) by ± 5% and ± 10%. RESULTS: The predictions show that small changes, ± 5%, in the doubling-time, tα for the rate of increase in the number of new infections, can have a major effect, both positive and negative, on the course of the pandemic. The model predicted that the number of persons infected with the virus would reach 1 million within 8 years. A 5% longer tα would reduce the number of infected persons by ~ 75%. In contrast, a 5% shorter doubling-time would increase the number of infections over 8 years to ~ 9 million when the number of infectious persons would exceed 100,000 at the end of 2022. The pandemic is predicted to have disappeared by the end of 2024. DISCUSSION: Predictions for the course of the COVID-19 pandemic in Germany based on the status quo up to July 13, 2020 have been obtained using the modified Bateman SIZ model. There are several important assumptions necessary to apply the model and thus the results must be interpreted with caution. The model, previously used to predict the course of the COVID-19 pandemic in the city of Heidelberg (pop. 166,000) gives comparable predictive data for the whole of Germany (pop. 83 million) and thus appears to be both sensitive and robust. CONCLUSION: Since a shorter doubling-time for the number of infectious persons by only 5% would result in a major clinical emergency, interventional measures such as vaccination are urgently needed. Taking into consideration that a SARS-CoV-2 vaccine is not yet available and the efficacy of the Corona-Warn-App has yet to be shown, a relaxation in the lockdown conditions in Germany in 2020 appears premature.