Nationwide estimates of SARS-CoV-2 infection fatality rates and numbers needed to vaccinate for COVID-19 vaccines in 2024 in Austria.

BACKGROUND

Post-pandemic years are characterized by widespread previous population immunization against COVID-19. Whether and for whom COVID-19 vaccinations are still justified is unclear. We use nationwide estimates of IFR and literature-derived estimates of vaccine effectiveness (VE) to calculate numbers needed to vaccinate to prevent one COVID-19 death (NNV) and for one life-year saved (LYS) in Austria in 2024.

METHODS

In this retrospective analysis, we calculate SARS-CoV-2 IFR during 2024 in Austria according to previously published wastewater-based infection estimates and available mortality data. Using literature-derived VE estimates, we calculate NNV to prevent one COVID-19 death and for one LYS in strata according to age groups, nursing home residency and vaccination in 2024. We repeat analyses with sensitivity range values of parameters.

RESULTS

In 2024, total IFR was .048%. NNV (LYS) in the age groups 0-19, 20-39, 40-59, 60-74 and 75-84 years was very high: i.e. 5,497,526 (151,570), 2,432,498 (92,614), 415,714 (24,777), 35,925 (3748) and 4882 (1009), respectively, in community dwellers. In the 85+ years age group, IFRs of unvaccinated/vaccinated were .91%/.77% for community dwellers and 1.22%/1.04% for nursing home residents. The 85+ year age group had NNV estimates of 1215 and 907 (LYS: 525 and 1896) in community dwellers and nursing home residents, respectively. Sensitivity analyses yielded LYS < 1000 only under some favourable assumptions in the 75-84 and 85+ years old age strata.

CONCLUSIONS

In 2024 in Austria, SARS-CoV-2 IFR was low and NNV and LYS of COVID-19 vaccinations correspondingly non-favorably high, even for very old individuals.