WHO: People should wear masks in public even if it's not mandatory

What they're saying: Ugarte said wearing masks was "very important" for the protection of individuals during the pandemic. "This has also proven to be highly effective to reduce transmission," he said.

• "This is a measure that continues to be very relevant," complimenting other measures including physical distancing, Ugarte noted.
• "Regarding travelers and travel by plane, we know that the use of masks has reduced dramatically the transmission during traveling," he continued.
• "We've seen that in some countries, the use of masks has been reduced to voluntary levels, and at the same time they’ve reduced the detection of cases," Ugarte added. "We can't let our guard down."

Driving the news: Airlines and other travel companies dropped mask requirements in the U.S. after a federal judge struck down the Biden administration's rule mandating masks on planes, trains and other forms of public transportation.

• The U.S. Justice Department is appealing the ruling following a request from the CDC, which concluded that mandates remained necessary.

Go deeper: America's new mask divide