The World Health Organization announced new guidance Friday for people who have been fully vaccinated against the coronavirus that differed significantly from that of the Centers for Disease Control and Prevention. The WHO advised people to continue wearing masks to contain the spread of the more deadly and more contagious Delta variant, first identified in India and designated “a variant of concern” by the CDC this week. WHO assistant director-general Dr. Mariangela Simao said, “People cannot feel safe just because they had the two doses. They still need to protect themselves. Vaccine alone won’t stop community transmission.” The CDC has advised fully vaccinated people that they can return to a life without face masks or limitations on seeing others indoors.