Serological surveys for Covid-19 are being conducted around the globe to understand the rate of prevalence of coronavirus antibodies in peo...
Serological surveys for Covid-19 are being conducted around the globe to understand the rate of prevalence of coronavirus antibodies in people. Blood samples collected from the general population and tested for IgG (Immunoglobulin G) antibodies. If a person is IgG positive, it means they had been infected with the coronavirus in the past, and is protected from future infection as long as a substantial level of the antibody remains in the body.
A major reason for conducting such surveys is the hope that a substantial proportion of the population has already been infected with the virus (possibly in an asymptomatic way) and so is immune to Covid-19. Epidemiologists call this state “herd immunity”
“Herd immunity occurs when enough people become immune to a disease to make its spread unlikely,” says the Harvard Medical School website. “As a result, the entire community is protected, even those who are not themselves immune. Herd immunity, it explains, “is usually achieved through vaccination, but it can also occur through natural infection”.
A stage of herd immunity would allow lockdown and other restrictions to be eased without fear of substantial numbers of people being infected.
Geneva survey
On June 11, The Lancet published the results of population-based serosurveys for anti-SARS-CoV-2 IgG antibodies in the Swiss city of Geneva for...
