Patients with mild symptoms of coronavirus can develop antibodies and they will develop the immune to the virus for several weeks or more, Medicalxpress reported referring to the French researchers.
According to them, the results, which have not yet been reviewed, were "encouraging," because little is known about the mechanisms of immunity against the new COVID-19, especially in people with minor and mild symptoms of the disease.
"We knew that people with severe forms of the disease developed antibodies within 15 days of the onset of symptoms," said Arnaud Fontanet, head of the global health department at the Institut Pasteur, which conducted the research with the University Hospital in Strasbourg.
"We now know that this is also true for those who develop minor forms, even if the rates of antibodies are probably weaker."
The study was conducted on 160 employees in two hospitals in Strasbourg, who had a mild form of coronavirus.
Two types of serological tests, which aim to look for a previous infection, indicated that almost all health workers—153 out of 160 in one case, 159 out of 160 in the other—had developed antibodies within 15 days after the onset of infection.
Using a separate test to determine if an antibody can neutralize the virus, a study found that about 98 percent of volunteers had these antibodies between 28 and 41 days after the first signs of infection.
Researchers said that the neutralizing activity of antibodies increases over time.
Olivier Schwartz, head of Pasteur's virus and immunity unit, said the objective would now be to monitor the "persistence of the antibody response and their capacity to neutralise" the virus over the longer term.