The CDC upgraded its guidance acknowledging that cloth masks are not as effective as surgical and N95 masks to protect against COVID-19 as the highly contagious Omicron variant continues to drive a record-breaking number of cases across the country. Rutgers microbiologist Martin Blaser, director of the Center for Advanced Biotechnology and Medicine, explains the reason for the evolving guidance and what to do if you only have a cloth mask available. To read the full story.