WHO says asymptomatic people can spread COVID-19, explains earlier comment was misunderstanding

A scientist with the World Health Organization has walked back comments made Monday when she said asymptomatic spread of COVID-19 is "very rare."

But the idea that people without symptoms can infect others is one of the major reasons stay-at-home orders were issued and communities have been socially distancing in the first place.

The statement from WHO's technical lead on COVID-19 set off a firestorm of comments on Twitter. But the epidemiologist, Dr. Maria Van Kerkhove, says it was a misunderstanding.

"I was responding to a question, I wasn't stating policy of WHO," Dr. Van Kerkhove said.

According to the doctor and WHO's technical lead on COVID-19, when she said, "It still appears to be rare that asymptomatic individuals actually transmit onward," she was referring to results of a small number of studies, not what we know globally about the novel coronavirus.

"We do know that some people who are asymptomatic or don't have symptoms can transmit the virus," Van Kerkhove said.

But what we don't know is the extent to which this is happening.

Experts say the majority of cases are spread through people with symptoms. But Dr. Michael LeVasseur, professor of epidemiology at Drexel University, says many studies also show people are contagious before they have symptoms, or pre-symptomatic.

"And that's really what's important because the things we have to worry about, wearing masks, social distancing, those things are going to be the same whether it's a large amount of asymptomatic or pre-symptomatic transmission, it's all a matter of degree," Dr. LeVasseur said.

And he reminds everyone, nothing has changed. The virus is still out there and we can't let our guards down yet.