As states reopen from stay-at-home orders, many, including California, are now requiring people to wear face coverings in most public spaces to reduce the spread of COVID-19.

Both the Centers for Disease Control and Prevention (CDC) and the World Health Organization now recommend cloth masks for the general public, but earlier in the pandemic, both organizations recommended just the opposite. These shifting guidelines may have sowed confusion among the public about the utility of masks.

But health experts say the evidence i