Barely three months after suggesting that vaccinated people no longer needed to wear masks, indoors or out, the US Centers for Disease Control and Prevention has now recommended people to resume wearing masks amid the surging delta variant, the media reported.

Speaking to reporters in an afternoon news briefing, Rochelle Walensky, director of the Centers for Disease Control and Prevention, expressed disappointment and dismay that the summer surge in cases, driven by the delta variant’s startling transmissibility and low vaccination rates in many areas, had forced the agency to reimpose its guidance that was lifted in May, the Washington post reported.

“It is not a welcome piece of news that masking is going to be a part of people’s lives who have already been vaccinated,” Walensky said. “This new guidance weighs heavily on me.”

The new guidance advised that people who live in high-transmission communities wear masks in indoor public spaces, even if they’ve been vaccinated. It also recommended that vaccinated people with vulnerable household members, including young children and those who are immunocompromised, wear masks indoors in public spaces, the report said.

The agency also called for universal masking for teachers, staff members and students in schools, regardless of their vaccination status. The CDC continues to recommend that students return to in-person learning in the fall.

In addition, the agency also now says that fully vaccinated people should get tested if they have any covid-19 symptoms or if they were recently exposed to someone who had a suspected or confirmed infection. Fully vaccinated Americans also should isolate if they test positive for the coronavirus or are experiencing symptoms, it said.

Walensky described the delta variant as, in effect, a different virus, capable of generating outbreaks of infection even among people who are vaccinated. “The delta variant is showing every day its willingness to outsmart us and to be an opportunist in areas where we have not shown a fortified response against it,” she said.

The concern was also echoed by US top infectious disease expert Dr Anthony Fauci, who said that “the situation has clearly changed” since May 13, the Post reported.

“Vaccinated people are transmitting it, and the extent is unclear, but there’s no doubt they’re transmitting it. People who are vaccinated, even when they’re asymptomatic, can transmit the virus, which is the scientific foundation of why this recommendation is being made,” Fauci was quoted as saying.

The US continues to be the worst-hit country with the world’s highest number of cases and deaths at 34,603,658 and 611,409, respectively, according to the latest update by Johns Hopkins University on Wednesday morning.