Excess mortality in individuals with and without COVID-19 vaccination in the Netherlands in 2021

Abstract

Abstract Background The COVID-19 pandemic greatly affected public health, evident in higher mortality rates in 2020-2022. COVID-19 vaccinations reduced global mortality, though this may vary across subpopulations. We aimed to study the role of COVID-19 vaccination in excess mortality by examining individuals with and without COVID-19 vaccine while accounting for characteristics such as income and frailty. Methods In this observational study, electronic health record data from general practitioners participating in the Nivel Primary Care Database were linked to demographic data and COVID-19 vaccination data. Patients were categorized in age groups, based on vaccination invitation dates, with the index date set as vaccination date for vaccinated individuals and the expected vaccination date for nonvaccinated ones. Expected mortality rates were calculated using 2015-2018 data, accounting for season, sex, income, migration background, palliative care, and frailty. We compared expected mortality to observed mortality in 2021 to determine excess mortality. Results Preliminary results show that nonvaccinated individuals (n = 160.253) were younger, and less frail, but more often received palliative care than vaccinated individuals (n = 819.363). In nonvaccinated individuals, excess mortality in the three months after expected vaccination ranged from 22-61% for 36-60 year olds to 209-233% for the 81+ year olds. In vaccinated individuals, excess mortality ranged from -64- -61% in 36-60 year olds to 2-4% in 81+ year olds. When not correcting for palliative care, excess mortality estimations increased significantly in nonvaccinated individuals (e.g. for 81+ year olds: 504%-514%). Conclusions Excess mortality was hardly present in vaccinated subgroups, while it was high in all nonvaccinated subgroups. Our study shed light on characteristics of nonvaccinated individuals, who require special attention during future vaccination programs to prevent excess mortality. Key messages • Excess mortality in the three months after (expected) COVID-19 vaccination was high among nonvaccinated individuals and hardly observed amongst vaccinated individuals. • Routine care data could help identify terminally ill individuals, who are overrepresented amongst nonvaccinated individuals, and mitigate the so called healthy vaccinee bias in vaccination research.