Wearing a tight-fitting mask or a double mask can dramatically decrease exposure to and spread of COVID-19, a crucial defense against emerging new variations of the virus, the CDC reported.

In lab tests with dummies, exposure to potentially infectious aerosols decreased by more than 90% when tight or double masks were used, the CDC said.

“Cases hospitalizations and deaths are still very high”, - said Dr. Rochelle Walensky, head of the Centers for Disease Control and Prevention, at a White House coronavirus briefing. “Now is not the time to roll back mask requirements”.