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.
More than 300,000 of the 1.87 million coronavirus cases across the world have recovered, WHO officials noted, adding that they need more data from recovered patients to understand their antibody response, whether that gives them immunity and for how long.
The U.S. Centers for Disease Control and Prevention has said that it is developing a test to detect the presence of coronavirus antibodies to determine if a person could be immune to the disease. While such a test can determine who has been exposed to the virus, it’s not clear if it can identify those immune to reinfection, according to the WHO.
“While Covid-19 accelerates very fast, it decelerates much more slowly. In other words, the way down is much slower than the way up,” WHO Director-General Tedros Adhanom Ghebreyesus said at a press conference at the organization’s Geneva headquarters on Monday. “That means control measures must be lifted slowly and with control. It cannot happen all at once.”