Transcript for Officials in Asia push back on need for all to wear face masks
And what about masks? If Americans have them, should they be wearing them? Would they help? The medical community doesn't want a run on masks. But what the scientists are saying if you have one. And what president trump said about this just moments ago. Here's Steve osunsami. Reporter: Health authorities in Asia, where the numbers of covid-19 cases are improving, say that Americans have it all wrong with face masks. The head of the Chinese center for disease control tells "Science" magazine that "The big mistake in the U.S. And Europe is that people aren't wearing masks. Many people have asymptomatic or presymptomatic infections. If they are wearing face masks, it can prevent droplets that carry the virus from escaping and infecting others." They believe that even masks made of simple fabrics are helpful. Jeremy Howard, a research scientist at the university of San Francisco, has looked at data from South Korea, Hong Kong, and Taiwan. And they all tell the same story, which is that wearing a mask can decrease transmission by up to 50%. Reporter: In Geneva today, the world health organization came out and said the exact opposite. We don't generally recommend the wearing of masks in public. Reporter: Dr Anthony Fauci says part of the issue is supply. That if health workers weren't struggling with a shortage of masks, authorities might recommend them for everyone. We're starting to re-examine the possibility that if there are enough masks, should everyone be wearing masks? Reporter: The president just spoke on this issue, and he said he's open to that idea, too. His administration may recommend that all Americans wear masks L the time for a short period of time. Steve, thank you. And in a moment, Dr. Jen Ashton with your questions.
This transcript has been automatically generated and may not be 100% accurate.