COVID-19 vaccine effectiveness against mortality and risk of death from other causes after COVID-19 vaccination, the Netherlands, January 2021-January 2022

Abstract

AbstractBackgroundWe aimed to estimate vaccine effectiveness (VE) against COVID-19 mortality, and to explore whether an increased risk in non-COVID-19 mortality exists in the weeks following a COVID-19 vaccine dose.MethodsNational registries of causes of death, COVID-19 vaccination, specialized health care and long-term care reimbursements were linked by a unique identifier using data from 1 January 2021 to 31 January 2022. We used Cox regression with calendar time as underlying time scale to: 1) estimate VE against COVID-19 mortality after primary and first booster vaccination, per month since vaccination and 2) estimate risk of non-COVID-19 mortality in the 8 weeks following a first, second or first booster dose, adjusting for birth year, sex, medical risk group and country of origin.ResultsVE against COVID-19 mortality was >90% for all age groups two months after completion of the primary series. VE gradually decreased thereafter, to around 80% at 7-8 months post-primary series for most groups, and around 60% for elderly receiving a high level of long-term care and for people aged 90+ years. Following a first booster dose, the VE increased to >85% in all groups. The risk of non-COVID-19 mortality was lower or similar in the 8 weeks following a first primary, second primary or first booster dose compared to no vaccination, first or second dose, respectively, for all age and long-term care groups.ConclusionCOVID-19 vaccination greatly reduced the risk of COVID-19 mortality and no increased risk of death from other causes was seen at the population level.