Is wearing masks needed to prevent the novel coronavirus spreading?

Bruce Aylward: They play an important role in preventing the spread of COVID-19. Patients obviously have to wear masks when they're in contact with people who don't have the virus, health workers have to wear masks, and of course, contacts too.

The question then becomes the general population. You always have to strike a balance between what difference these measures make and the cost and effect of wearing the masks, because you could have shortages that prevent them from getting into the hands of people who really need them. But people often say to me, "So was that a mistake in China with the masks?

And I say, "Well, look, we have never before in history put masks on 1.4 billion people and looked at the effect.

So this is something we have to study and learn from. It wasn't our recommendation, and China did some things differently. And, you know, China has turned around the outbreak and I would not quickly rule out anything that it did.

I think we have to study these things. But the really important thing was the speed with which you found cases and found contacts and took care of them.

Bruce Aylward, a Canadian epidemiologist and leader of the WHO-China Joint Mission on COVID-19, shares his insights with China Daily in Geneva on March 6.