The World Health Organization this week dropped a potential bombshell with a statement about asymptomatic coronavirus transmission, only to walk it back less than 24 hours later.
WHO's Dr. Maria Van Kerkhove during a briefing on Monday made headlines by declaring that it "seems to be rare that an asymptomatic person actually transmits" COVID-19 "onward to a secondary individual. It's very rare." That would be great news, but experts were skeptical and confused, with former FDA Commissioner Scott Gottlieb calling this a "premature conclusion."
On Tuesday, the WHO held a live stream to clarify the situation and offer some massive caveats. Kerkhove explained that this "very rare" conclusion was in fact only based on a "very small subset of studies" and that "we need to better understand" how many people who are asymptomatic transmit the coronavirus, as this is a "major unknown."
She also said the "very rare" phrase created a "misunderstanding" and cited other models that went unmentioned on Monday but that, on the contrary, suggest asymptomatic transmission might be far more common.
"Some modeling groups have tried to estimate what is the proportion of asymptomatic people that may transmit," she said. "And these are estimates ... But some estimates of around 40 percent of transmission may be due to asymptomatic."
Dr. Mike Ryan added that the comment from Monday was "clearly misinterpreted, or maybe we didn't use the most elegant words" and Kerkhove additionally clarified that asymptomatic refers to someone who doesn't have symptoms and never develops them.
The WHO came under heavy criticism for this definitive-sounding declaration followed by the next day's walk back, with journalist Yashar Ali decrying the organization's "stunning incompetence."