(USA TODAY) The World Health Organization has urged fully vaccinated people to continue wearing masks indoors and practice social distancing as the delta variant surges in many parts of the world. 

“People cannot feel safe just because they had the two doses. They still need to protect themselves,” said Dr. Mariangela Simao, WHO assistant director-general, during a news briefing Friday. 

The Centers for Disease Control, however, told vaccinated Americans in May that they no longer needed to wear masks indoors. CDC officials pointed to the guidance Monday and gave no indication it would change, according to the New York Times. 

But some areas around the country are still urging vaccinated residents to wear masks indoors.

"Until we better understand how and to who the delta variant is spreading, everyone should focus on maximum protection," the Los Angeles County of Public Health said Monday. The delta variant now accounts for 50% of active cases in Los Angeles, said officials Thursday, while it accounts for 1 in 5 of cases around the country. 

23 states had more cases in the latest week than in the week before, an analysis of Johns Hopkins University data shows. 26 states had more deaths than a week earlier.