Vaccine effectiveness in preventing hospital admission has been slightly lower in the last 8 weeks compared to the entire period from 11 July to 7 December 2021. One of the causes is that people who have recently been admitted to hospital completed their vaccination series longer ago, on average, than people who were admitted in summer. Another cause is that virus circulation has increased in recent months. Vaccine effectiveness in preventing ICU admissions remains very high for all age groups.
Vaccine effectiveness among people aged 70+
Vaccine effectiveness in preventing hospital admissions is lower among people aged 70 years and older than among people under 70. In the past eight weeks, it was 82% against hospital admission and 93% against ICU admission. For the entire period, those figures were 85% and 94% respectively. Possible effects of booster vaccination have not yet been included in this update.
Vaccinated people much less likely to be admitted to hospital or ICU than unvaccinated people
In the past eight weeks, the chance that a fully vaccinated person with the coronavirus SARS-CoV-2 would be admitted to hospital was 9 times lower than for a non-vaccinated person. The chance of ICU admission was 20 times lower.*
The analysis is based on NICE data on hospital admissions of patients with COVID-19 admitted until 7 December 2021. The data was enriched on 8 December 2021 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
More information is available in previous updates on effectiveness of COVID-19 vaccines.
* These probabilities can be derived directly from vaccine effectiveness: reduced probability=100/(100-vaccine effectiveness).