Coronavirus humoral immunity may decline in months after infection - study
Researchers called for a larger study of humoral immunity, saying that their small study emphasizes the need for further research.
By EVE YOUNGA medic of the regional hospital receives Russia's "Sputnik V" vaccine shot against the coronavirus disease (COVID-19) in Tver, Russia October 12, 2020. (photo credit: REUTERS/TATYANA MAKEYEVA/FILE PHOTO)
A new preliminary study from Chonqing Medical University found a decline in some indicators of humoral immunity in 20 patients who had recovered from COVID-19. Humoral immunity is the immune response mediated by antibodies which protect the host in three ways: by binding to pathogens to reduce or prevent their toxic effect or infectivity; coating pathogens, which facilitates other immune responses against them; and activating other immune responses, according to the journal Nature. The study found a decline over the course of eight months in neutralizing antibodies (NAbs) and IgG, the anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike receptor-binding domain. It also found a correlation between IgG and NAb levels seen at the beginning of the study. This shows that eight months following recovery, protective immunity levels may not be the same.The study looked at people who had recovered from SARS-CoV-2 over the course of the eight months following their recovery. In some of the patients, some indicators of immunity decreased below detectable levels during that period.This is significant for those who have been infected with the virus, and it may have implications for vaccinations.“Facing the challenge of the second wave of SARSCoV2, the risk of reinfection by the currently dominant SARSCoV2 SG614 variants is worthy to be considered, especially for Chinese convalescent patients infected by wild type SARSCoV2,” said the researchers.Researchers called for a larger study of humoral immunity, saying that their small study emphasizes the need for further research.
