It is well accepted that COVID-19-related mortality shows a strong age dependency.
However, temporal changes in the age distribution of excess relative mortality between
waves of the pandemic are less frequently investigated. We aimed to assess excess
absolute mortality and the age-distribution of all-cause mortality during the second
and third waves of the COVID-19 pandemic in Hungary compared to the same periods of
non-pandemic years. Rate ratios for excess all-cause mortality with 95% confidence
intervals and the number of excess deaths for the second (week 41 of 2020 through
week 4 of 2021) and third waves (weeks 7–21 of 2021) of the COVID pandemic for the
whole of Hungary compared to the same periods of the pre-pandemic years were estimated
for 10-year age strata using Poisson regression. Altogether, 9771 (95% CI: 9554–9988)
excess deaths were recorded during the second wave of the pandemic, while it was lower,
8143 (95% CI: 7953–8333) during the third wave. During the second wave, relative mortality
peaked for ages 65–74 and 75–84 (RR 1.37, 95%CI 1.33–1.41, RR 1.38, 95%CI 1.34–1.42).
Conversely, during the third wave, relative mortality peaked for ages 35–44 (RR 1.43,
95%CI 1.33–1.55), while those ≥65 had substantially lower relative risks compared
to the second wave. The reduced relative mortality among the elderly during the third
wave is likely a consequence of the rapidly increasing vaccination coverage of the
elderly coinciding with the third wave. The hugely increased relative mortality of
those 35–44 could point to non-biological causes, such as less stringent adherence
to non-pharmaceutical measures in this population.
