Excess mortality analysis for Germany for all three COVID-19 waves in 2020 - 2021

Weber, A.

Background and Aims: The reported case and death numbers of the coronavirus disease (COVID-19) are often used to estimate the impact of COVID-19. We observe that during the second half of the first and second waves, the COVID-19 deaths are significantly higher than the excess mortality. We attribute the difference to the pre-dying effect. We then compare the excess mortality to the official COVID-19 death numbers and calculate the infection fatality rates (IFRs) and the percentage of infected individuals from excess mortality for different age bands. We also compare the impact of COVID-19 to past influenza waves and analyze the vaccination effect on excess mortality. Methods: We forecast the baseline mortality from official data on deaths in Germany. Distributing a part of excess mortality into the near future, we lower the baseline simulating the pre-dying effect. From there, we compare the excess mortality to official COVID-19 deaths. From the observed mortality deficit, we estimate the percentage of infected individuals and then estimate the age-dependent IFRs. Results: In the first wave, we find an overall excess mortality of ca. 8 000. For the second wave, the overall excess mortality adds up to ca. 56 000. We find, that the pre-dying effect explains the difference between the official COVID-19 deaths and excess mortality in the second half of the waves to a high degree. Attributing the whole excess mortality to COVID-19, we find that the IFRs are significantly higher in the second wave. In the third wave, we find an excess mortality in mid-age bands which cannot be explained by the official COVID-19 deaths. For the senior band 80+, we find results in favor of a strong and positive vaccination effect for the third COVID-19 wave. Conclusions: We conclude that in the first and second COVID-19 waves, the COVID-19 deaths explain almost all excess mortality when the pre-dying effect is taken into account. In the third wave in 2021, the excess mortality is not very pronounced for the 80+ age band, probably due to vaccination. The partially unvaccinated 40-80 age group experiences a pronounced excess mortality in the third wave while there are too few official COVID-19 deaths to explain the excess. The no-vaccination scenario for the 80+ age band results in a similarly high excess mortality as for the more younger age bands, suggesting a very positive vaccination effect on reduction of COVID-19 deaths.