According to a study published on Tuesday, levels of antibodies against the novel coronavirus increased in Iceland and then remained stable for four months in more than 90% of patients with Covid-19.
File photo: A person wearing a protective face mask sees an example of a virus outside a regional science center, as the city and surrounding areas face local restrictions, from local lockouts in the area. To avoid, during coronavirus disease. (Coved-19) On August 3, 2020, an outbreak broke out in Oldham, UK.
In previous studies, there was a sharp drop in antibody levels of Covid-19 within a few months, raising questions about the survival period that could provide infection.
Carrie Stephenson, chief executive of Decode Genetics, which conducted the study, said the new research could have implications for re-examination risks and vaccine immunizations.
To find out how many people in Iceland were infected with the new coronavirus and to learn more about the immune status after recovery, the researchers measured antibody levels in more than 30,000 Icelanders.
Based on the results, they estimate that about 1% of the population was infected. Of that group, 56% confirmed the test after a gold standard PCR laboratory test. Another 14% were not formally tested, but were isolated after exposure to the virus. In the remaining 30%, previous infections due to antibody tests were detected.
Of the 1,215 people confirmed to be infected by PCR, 91% had antibody levels that rose and then rose during the first two months after the test, the researchers said.
The results, published in The New England Journal of Medicine, focus on the same population in the same country, so the results may not be the same in other parts of the world with different populations.
However, the study shows how carefully antibody tests can determine the exact spread of the infection, Stephenson said.
An editorial accompanying the study warned that it was unclear if antibodies in cured patients would prevent them from reactivating.
However, it suggests that antibody testing may be a cost-effective alternative to single infection testing, and may work better in population surveys as countries look to rehabilitate their economies and schools.
Reporting by Vishwada Chandra in Bangalore; Edited by Nancy Lapid and Bill Barcroft