54% Finns developed hybrid immunity against COVID-19: study

Over half of Finns had developed antibodies to novel coronavirus (SARS-CoV-2) after either vaccination or previous infection by the end of 2022, the Finnish Institute for Health and Welfare (THL) said in a new study on Monday, reported Xinhua.

Hybrid immunity provides lasting protection against severe COVID-19 disease, it said.

The institute has been monitoring the presence of antibodies following infection with the novel coronavirus in the Finnish population since April 2020.

Randomly selected adults aged 18-85 from all over the country were invited to participate in the study. The researchers collected blood samples from 9,800 individuals.

They also monitored the occurrence of antibodies produced by the vaccines.

According to the study, the prevalence of antibodies indicating SARS-CoV-2 infection increased strongly in 2022. The prevalence surged from less than seven percent at the end of 2021 to 54 percent between October and December 2022.

Based on data from the vaccination register and antibody research, an estimated 51 percent of people aged 18-85 in Finland had developed hybrid immunity produced by a combination of vaccination and infection by the end of 2022.

"Although vaccines have not been able to prevent infections caused by new variants, they have provided protection against severe disease for a large part of the population. Infections strengthen protection against serious disease even more," THL's research manager Merit Melin said in the press release.