Background: The characteristics of the COVID-19 pandemic in Europe have changed since the initial outbreak in 2019 due to the emergence of more contagious mutant strains, notably the B.1.1.7 variant. This has resulted in the rapid implementation of vaccination programs in an effort to control the spread of the disease.
Aims: To model the effect of vaccination on the course of the pandemic in Germany taking into account observational data and the appearance of viral mutant B.1.1.7.
Materials and methods: An effect model based on the Batman-SIZ algorithm was developed, taking into account both the parent and the B.1.1.7 mutant strains of the SARS-CoV-2 coronavirus and using input parameters obtained from observational data for January - March 2021.
Results: Effect-modelling using 3 different vaccination scenarios with different rates of vaccination involving 67 million persons (priority groups 1 - 5) and completed within 134 days compared to 318 days beginning February 24, 2021, showed a reduction in the number of infected persons from ca. 12.5 million to ca. 4.5 million with quantitively similar benefits regarding the occupancy and a critical burden on ICU facilities.
Conclusion: The effect of vaccination in reducing the daily number of new infections, the total number of infections and the occupancy of intensive-care facilities in hospitals is proportional to the speed with which the target population are vaccinated.