WHO scrambling after mixed messages on COVID-19 advice
LONDON — It’s an issue that’s been argued about for months, both by experts and by people strolling through parks all over the world: Can people who don’t feel sick spread the coronavirus, and if so should we all be wearing masks to stop it?
Even the World Health Organization can’t seem to get it straight.
On Tuesday, the U.N. health agency scrambled to explain seemingly contradictory comments it has made in recent days about the two related issues.
The confusion and mixed messages only makes controlling the pandemic that much more difficult, experts say.
“If you are giving them confusing messages or they’re not convinced about why they should do something, like wear masks, they will just ignore you,” said Ivo Vlaev, a professor of behavioral sciences at the University of Warwick.
The communications debacle highlighted WHO’s change to its longstanding mask advice — a revision that was made months after many other organizations and countries already recommended people wear masks.
On Friday, WHO changed its mask advice, recommending that people wear fabric masks if they could not maintain social distancing, if they were over age 60 or had underlying medical conditions.
But when Maria Van Kerkhove, WHO’s technical lead on COVID-19 was asked about the frequency of this kind of transmission this week, she said “It still appears to be rare that asymptomatic individuals actually transmit onward.”
On Tuesday, Van Kerkhove said she was referring to a few studies, not the complete picture.
Still, many other scientists were stunned by the description of asymptomatic spread as “rare,” saying plenty of evidence exists that people can spread the disease before suffering symptoms.
Here’s what scientists say and experts recommend based on what is known:
Can people who don’t feel sick spread the disease?
We don’t know. WHO has maintained for months that the vast majority of COVID-19 spread is from people with symptoms like a fever or cough, and that transmission from people who don’t feel sick is not thought to be a major driver of the disease.
At a social media event Tuesday to try to clear up confusion, WHO’s emergencies chief, Dr. Michael Ryan, said “both symptomatic and asymptomatic individuals are part of the transmission cycle” but that it was unclear how much each contributed to disease spread.
Does wearing a mask help?
Wearing a mask might not protect you from getting sick — your eyes are likely still exposed — but health experts think that it may prevent you from spreading the disease unknowingly. COVID-19 is spread via respiratory droplets, so wearing a mask will stop those droplets from reaching others. While most spread is thought to happen by coughing and sneezing, Ryan said there is some suggestion that even acts like singing or shouting could spread the virus from people who don’t yet show symptoms.
Why don’t we know for sure?
It’s complicated, especially since the virus was only identified in December. Some scientists said WHO’s distinction between people who are truly asymptomatic — those who are infected by COVID-19 but never show symptoms — and those who are pre-symptomatic and develop symptoms later — is part of the problem. While truly asymptomatic people are likely not responsible for significant virus spread, several studies have documented people spreading the disease before they get sick — and some experts say recognizing and stopping this kind of transmission is critical to controlling the pandemic. Detailed studies and testing of people who test positive for the coronavirus but don’t show symptoms to determine if they spread the disease are needed — and few have been done so far.