COVID-19 vaccines work well in preventing people from being admitted to hospital or ICU for COVID-19, according to a new analysis by RIVM. The vaccines offer fully vaccinated people 95% protection against hospital admission and 97% against ICU admission. The chance that a fully vaccinated person with the coronavirus SARS-CoV-2 will be admitted is 20 times lower than for a non-vaccinated person. The chance of ICU admission for a fully vaccinated person is 33 times lower.
The study shows that the vaccines protected as much in the period when the delta variant was most present (4 July to 12 August) as in the period when the alpha variant was most present in the Netherlands (4 April to 29 May).
Vaccination status in hospital admissions since 4 April
15,222 people with COVID-19 were admitted to hospital between 4 April and 20 August 2021. 88.0% of these people were unvaccinated, 7.4% were partially vaccinated and 4.6% were fully vaccinated. In recent weeks, the number of hospital admissions among unvaccinated people over 70 was about the same as hospital admissions among over-70s who are fully vaccinated, which is a much larger group.
No decrease in effectiveness over time
The vaccination campaign started more than 8 months ago. In those eight months, more than 10 million people have been fully vaccinated. This analysis does not show any evidence that the effectiveness of the vaccines decreases in the first months after vaccination. It should be noted, however, that only 1 million people had been fully vaccinated as of four months ago. RIVM will therefore continue to monitor COVID-19 vaccine effectiveness in relation to hospital and ICU admissions over time.
Effectiveness of different vaccines
The study also differentiated between type of vaccine and effectiveness. Most people in the Netherlands have been vaccinated with the Pfizer/BioNTech vaccine. The analysis shows that this vaccine protects more than 98% of fully vaccinated people under the age of 70 from hospital and ICU admission. This means that the risk of hospital and ICU admission for these people is 50 times lower than for non-vaccinated people.
The Moderna vaccine seems to be somewhat less effective in preventing hospital admissions. Almost one million people received the Moderna vaccine, and many of these people are in the medical high-risk groups. It is known that the vaccines may be less effective in people who are in medical high-risk groups. This may explain Moderna’s lower effectiveness in this analysis.
The COVID-19 vaccines made by AstraZeneca and Janssen were also administered less frequently in the vaccination campaign in the Netherlands. As a result, the effectiveness of these vaccines was determined with slightly less precision in these analyses.