Susan Walsh/AP Photo He said Americans vaccinated against COVID-19 need to "make that transition." The CDC said last month that vaccinated people can take off their masks at small outdoor gatherings. Dr. Anthony Fauci said people who are vaccinated against COVID-19 don't need to wear masks outside, backing up earlier guidance from the Centers for Disease Control and Prevention. Fauci, the director of the National Institute of Allergy and Infectious Diseases, told "CBS This Morning," "We've got to make that transition." "If you are vaccinated, you don't have to wear a mask outside," he added. "It would be a very unusual situation, if you were going into a completely crowded situation where people are essentially falling all over each other, then you wear a mask. But any other time, if you're vaccinated and you're outside, put aside your mask. You don't have to wear it."