A top official with the World Health Organization has walked back statements that the spread of COVID-19 from people who do not show symptoms is “very rare,” amid backlash from experts who have questioned the claim.
A top official with the World Health Organization has walked back statements that the spread of COVID-19 from people who do not show symptoms is “very rare,” amid backlash from experts who have questioned the claim due to a lack of data.
Maria van Kerkhove, an infectious disease epidemiologist and the COVID-19 technical lead for the WHO, said Monday that the available data from published research and member countries had shown asymptomatic cases were not a significant driver for the spread of the virus.
“From the data we have, it still seems to be rare that an asymptomatic person actually transmits onward to a secondary individual,” she said at a media briefing in Geneva on Monday. “It’s very rare.”
On Tuesday, Van Kerkhove aimed to clear up “misunderstandings” about those statements in an updated briefing, stressing that she was referring to “very few studies” that tried to follow asymptomatic carriers of the virus over time to see how many additional people were infected.
“I was responding to a question at the press conference, I wasn’t stating a policy of WHO,” she said. “I was just trying to articulate what we know.”
Van Kerkhove said she didn’t intend to imply that asymptomatic transmission of the virus globally was “very rare,” but rather that the available data based on modelling studies and member countries had not been able to provide a clear enough picture on the amount of asymptomatic transmission.
“That’s a big, open question,” she said. “But we do know that some people who are asymptomatic, some people who don’t have symptoms, can transmit the virus on.”
WHO did ‘questionable job’ of communicating
Dr. Isaac Bogoch, an infectious disease physician at Toronto General Hospital, said there has been conf