The World Health Organization on Tuesday walked back its recent claim (from one day earlier) that asymptomatic spread of COVID-19 is "very rare," now saying the question is "really complex," CNBC reported.
Here's what Dr. Maria Van Kerkhove, head of WHO's emerging diseases and zoonosis unit, said Monday about the potential for people with no symptoms to spread COVID-19 to others:
From the data we have, it still seems to be rare that an asymptomatic person actually transmits onward to a secondary individual. It's very rare. … We have a number of reports from countries who are doing very detailed contact tracing. They're following asymptomatic cases. They're following contacts. And they're not finding secondary transmission onward. It's very rare.
Tuesday, Van Kerkhove said it's a "really complex question" and that their models show that as much as 40% of COVID-19 transmission may come from asymptomatic cases. From CNBC:
"We don't actually have that answer yet. There are some estimates that suggest that anywhere between 6% of the population and 41% of the population may be infected but not have symptoms within a point estimate of around 16%," she said on a live Q&A streamed across multiple social media platforms.
"The majority of transmission is from people who have symptoms and are spreading it through infectious droplets, she said. "But there are a subset of people who don't develop symptoms. To truly understand how many people don't have symptoms, we don't actually have that answer yet.
Dr. Mike Ryan, executive director of the WHO's emergencies program, said Van Kerkhove's Monday statements may have been "misinterpreted or maybe we didn't use the most elegant words to explain that."
If it's true that asymptomatic people don't spread COVID-19, or spread it very rarely, there would be little reason to continue with widespread lockdown policies. Governments and businesses could implement policies to isolate those with symptoms and allow those without symptoms to operate freely.