"Putting a face mask on does not mean that you stop the other practices," said May Chu, a clinical professor in epidemiology at the Colorado School of Public Health on the Anschutz Medical Campus who was not involved in either new study. "It does not mean you get closer to people, it does not mean you don't have to wash your hands as often and you can touch your face. All of that still is in place, this is just an add-on."