THL study: The effectiveness of Covid-19 vaccines against severe disease in the elderly is excellent

Publication date 15 Mar 2022

The effectiveness of the Covid-19 vaccines used in Finland against severe Covid-19 is good after two doses and excellent after three doses in the elderly aged 70 years and above. This is the result of a study conducted by the Finnish Institute of Health and Welfare (THL), which estimated the vaccine effectiveness against Covid-19 requiring hospitalization and intensive care. The study took into account the effect of age, presence of comorbidities and the recently emerged omicron variant.

The study found that the vaccine effectiveness against Covid-19-related hospitalization was initially 90 % after two doses. The effectiveness decreased slightly in the first six months after vaccination, but was still good three to six months after the second dose. After the third dose, the effectiveness increased to over 95 % and remained excellent for at least two to three months. 

“In the study the omicron variant was observed to have little effect on the decline in vaccine protection, but the protection against severe disease caused by omicron remained excellent at 90–95 % after the third dose. The study indicates no cause for concern about a decline in vaccine protection against severe Covid-19 after three doses of the vaccine, but longer-term monitoring is needed.”, tells Eero Poukka, medical specialist at THL. 

The study also found that the vaccine effectiveness against severe Covid-19 is slightly lower among people with comorbidities and among people aged 80 years and above. 

“We closely monitor the vaccine effectiveness through register-based analyses in order to improve the vaccination strategies. In the future, we will estimate vaccine effectiveness against deaths caused by Covid-19” says Ulrike Baum, statistician at THL.

Further information:

High vaccine effectiveness against severe Covid-19 in the elderly in Finland before and after the emergence of Omicron (medRxiv)

Eero Poukka
Medical Specialist
[email protected]

Ulrike Baum (in English)
[email protected]

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