World Health Organization officials said Monday not all people who recover from the coronavirus have the antibodies to fight a second infection, raising concern that patients may not develop immunity after surviving Covid-19.
“With regards to recovery and then reinfection, I believe we do not have the answers to that. That is an unknown,” Dr. Mike Ryan, executive director of WHO’s emergencies program, said at a press conference at the organization’s Geneva headquarters on Monday.
A preliminary study of patients in Shanghai found that some patients had “no detectable antibody response” while others had a very high response, said Dr. Maria Van Kerkhove, WHO’s lead scientist on Covid-19. Whether the patients who had a strong antibody response were immune to a second infection is “a separate question,” she added.