Antibody reactions to the coronovirus may wane over time, according to a study that showed a natural defense in Britons who had previously been exposed.
According to a study published Tuesday by Imperial College London and the Ipsos Mori polling service, 365,000 randomly selected British adults who tested themselves in September had antibodies in September, up from 6,000% in June.
Studies show that antibodies, a marker of exposure to coronovirus, may not be permanent in all infected people, adding to other research indicating that immunity may be reduced.
A small but growing number of patients with Kovid-19 have fallen ill twice, and it is unclear how long-term protection of antibodies against a vaccine will be. There are some protective injections in development that aim to stimulate so-called T cells that can fight the virus.
The study showed that those who tested positive, but did not show symptoms of Kovid-19, lost antibodies more often than those who had noticeable effects from the disease.