COVID-19 pandemic predictions using the modified Bateman SIZ model and observational data for Heidelberg, Germany: Effect of vaccination with a SARS-CoV-2 vaccine, coronavirus testing and application of the Corona-Warn-App

Published data show that the current progression of the COVID-19 pandemic in Heidelberg, Germany, despite the current lockdown, could continue into 2021 and become more severe. We have used the modified Bateman SIZ algorithm to predict the effects of interventional measures to control the COVID-19 pandemic. Model parameters, e.g., doubling time and rate of decrease in the number of infectious persons were obtained from published reports. Predictions were made for the status quo on June 1, 2020, and for interventional measures obtained for 4 scenarios. These included vaccination of the whole population using a SARS-CoV-2 vaccine having an efficacy of 50% and 100%, mass-testing for COVID-19 coronavirus and application of the Corona-Warn-App. The principle findings were 1) without new measures to control the pandemic, the daily number of infectious persons could reach a peak of > 4,500 daily within 18 months when > 67,000 persons would have been infected. This could be prevented by using a vaccine with 50% efficacy which was almost equally effective as a vaccine with 100% efficacy. Application of the Corona-Warn-App was the most effective method and more effective than testing for COVID-19. The methodology used has been described in detail to enable other researchers to apply the modified Bateman SIZ model to obtain predictions for COVID-19 outbreaks in other regions. Application of the model has been verified by independent investigators using different commercial software packages. The modified Bateman SIZ model has been verified and used to predict the course of the COVID-19 pandemic in Heidelberg. Lockdown measures alone are insufficient to control the pandemic during 2021. Vaccination, diagnostic tests, and use of the Corona-Warn-App with quarantine could successfully control the spread of the coronavirus infection in the community. The Corona-Warn-App applied correctly may be the most effective. The model showed that vaccination with 50% efficacy is almost as effective as vaccination with 100% efficacy.