May COVID-19 survivors be protected from re-infection? Scientists from Sweden have tried to answer this question.

According to Medportal.ru, scientists from the Swedish Public Health Agency involved 469 volunteers in the new study, who agreed to donate blood samples to determine antibodies to coronavirus. During the first test from October to December 2020, antibodies to SARS-CoV-2 were detected in 145 participants. A control study carried out in April confirmed the fact of the transferred infection in another 28 people.

About 85% of patients with positive test results suffered mild COVID-19. Almost all participants (95%) had two types of neutralizing antibodies to IgG infection: to S-protein and N-protein (nucleocapsid). In 8 samples, experts found only one type of antibody, and in 4 - none of them.

Scientists did not find a connection between the level of antibodies and the sex and age of a person, however, this level correlated with the severity of COVID-19: after a severe or moderate course, it was higher.

8 months after the first test, the level of antibodies to the S-protein remained stable in the first group of patients. However, the titer of antibodies to the N-protein was noticeably lower compared to the initial values. At the same time, not a single case of re-infection in this sample was recorded during this period.