The Centers for Disease Control and Prevention has changed its guidelines about masks and respirators a number of times over the past two years and gave its most recent update on Jan. 14, 2022. The update states that cloth face coverings offer the least protection from the coronavirus compared with surgical masks or N95-style masks. Christian L'Orange is a mechanical engineer who has been testing the performance of masks for the state of Colorado since the beginning of the pandemic. He explains the new CDC guidelines and the science of what makes for a good mask.
