Some airlines and public transit dropped mask mandates following a federal judge's ruling

Masks are no longer required on many major airlines and at some U.S. airports. Amtrak, Uber, and some public transit systems have also dropped mask requirements.

These changes come after a federal judge on Monday struck down the Center for Disease Control and Prevention's mask mandate.

Here & Now's Scott Tong talks with Saskia Popescu, epidemiologist and infectious disease expert at George Mason University, about the risks of taking public transit while COVID-19 infections are on the rise again.