People who get a booster vaccination have much more effective protection against COVID-19 hospital and ICU admission than people who are not vaccinated, and more effective protection than people who have only been vaccinated with the basic series. This protection also applies to infection with the Delta variant or Omicron variant. From 1 December 2021 to 22 February 2022, vaccine effectiveness for the COVID-19 booster vaccination was 94% against hospital admission and 98% against ICU admission. The risk of ICU admission after a booster vaccination was more than 50 times lower than the risk of ICU admission without vaccination. For people who only received the basic series of COVID-19 vaccinations, vaccine effectiveness was 76% against hospital admission and 91% against ICU admission. The risk of ICU admission after the basic series of COVID-19 vaccinations without a booster was more than 11 times lower than the risk of ICU admission without vaccination.
The effectiveness of the basic series of COVID-19 vaccinations in preventing hospital and ICU admissions decreases over time. This is mainly due to the emergence of the Omicron variant, with waning immunity over time after vaccination as a secondary factor. After a booster vaccination, vaccine effectiveness increases again in all age groups.
The analysis is based on NICE data on hospital admissions of patients with COVID-19 admitted until 22 February 2022. The data was enriched on 23 February 2022 with vaccination data from the COVID-19 Information and Monitoring System (CIMS). The method used to calculate vaccine effectiveness is explained in the report: Study: Effectiveness of COVID-19 vaccination against hospital and ICU admission in the Netherlands
Please note: raw data cannot be published due to its privacy-sensitive nature.