Booster vaccinations reduced the risk of dying from COVID-19 in 2022. The risk of death from other causes was also lower for people who had a booster jab than for people without a booster jab. These findings are from research by RIVM. However, the effect of a repeat vaccination wanes over time.
The Ministry of Health, Welfare and Sport (VWS) commissioned a study by RIVM and Statistics Netherlands (CBS) on the causes of excess mortality in 2022. This study picked up where the report for 2020 and 2021(in Dutch) left off. RIVM researched how effective the repeat vaccinations with the COVID-19 vaccines were in preventing death from COVID-19 and death in general. Also, RIVM researched the risk of death due to other causes than COVID-19 shortly after a booster vaccination.
Lower risk of death from COVID-19
There were three rounds of booster vaccinations in total between November 2021 and autumn 2022. Each successive repeat vaccination reduced the risk of death from COVID-19. One year after the first booster, the risk of death was still lower than for people who had not had that booster dose. This effect did not last as long after the spring vaccination in 2022. In the group of people aged 70 years and over in long-term care (most of whom were nursing home residents), the estimated vaccine effectiveness shortly after the repeat vaccination was lower than among other groups. It also waned more quickly.
Lower risk of death regardless of the cause of death
The booster vaccination not only reduced the risk of death from COVID-19. The overall risk of death was also lower among people who received a repeat vaccination. The risk of death from causes other than COVID-19 was investigated for the first 8 weeks after receiving the booster dose. In those weeks, the risk of death was also lower than for people who had not received the booster dose (or not yet).
Possible explanations
One possible explanation for these results is that people who did get a booster jab may have been healthier than people who did not. The coronavirus SARS-CoV-2 may also have played a role in some of the deaths, even if COVID-19 was not listed as a possible cause of death in those cases.
About the study
RIVM and Statistics Netherlands (CBS) carried out the study as commissioned by the Ministry of Health, Welfare and Sport (VWS). This was prompted by a motion in Parliament. The House of Representatives requested a study on excess mortality during the years of the COVID-19 pandemic. RIVM and CBS both conducted sub-studies based on their own expertise and available data.