The director of the Facilities for Illness Management and Prevention on Wednesday stood by recommendation that folks absolutely vaccinated in opposition to the coronavirus don’t have to put on masks in most conditions, however added that there are situations the place native authorities may impose extra stringent measures to guard the unvaccinated.

The feedback got here after the World Well being Group lately reiterated longstanding guidance that everyone, vaccinated or not, wear masks and take different precautions, following a world surge in infections of the highly contagious Delta variant. On Monday, Los Angeles County recommended that even fully vaccinated people wear masks indoors.

In Might, the C.D.C. suggested that fully vaccinated Americans could forgo masks in most settings. The company’s director, Dr. Rochelle P. Walensky, stated throughout a number of tv appearances on Wednesday that native adjustments to masking and distancing guidelines have been in keeping with these tips.

“We now have all the time stated that this virus is an opportunist, and in areas the place we nonetheless have charges of low vaccination, that’s the place the virus is prone to take maintain,” she stated on “Good Morning America.” “We’re nonetheless seeing uptick of circumstances in areas of low vaccination, and in that scenario we’re suggesting that insurance policies be made on the native stage.”

Dr. Walensky added that the W.H.O.’s blanket suggestion that each vaccinated and unvaccinated people put on masks was knowledgeable by its international purview. “The W.H.O. actually does should make suggestions for a whole world,” and plenty of nations have far much less entry to vaccines than the USA, she stated.

The Delta variant now accounts for about one in each 4 infections in the USA, in accordance with new estimates this week from the C.D.C. However circumstances throughout the nation have plummeted in current months, together with hospitalizations and deaths.

Nonetheless, the typical charge of U.S. vaccinations a day has decreased by about 75 percent from the height reported in mid-April. As of Tuesday, about 46 % of individuals of all ages and about 57 % of adults are absolutely vaccinated, in accordance with federal knowledge.

Vaccines persistently defend folks from the variants circulating in the USA, together with the Delta variant, Dr. Walensky famous on NBC’s “Today” present on Wednesday. However “native policymakers have to make insurance policies for his or her native surroundings,” she stated, particularly in elements of the nation with low charges of vaccination.

“These masking insurance policies are to not defend the vaccinated — they’re to guard the unvaccinated,” she added, noting that “all people ought to contemplate their very own scenario if they’d really feel extra comfy sporting a masks.”

In Los Angeles County, the place half of the population is fully vaccinated, well being officers beneficial that everybody put on masks indoors due to an uptick in cases and an increase in infections with the Delta variant. Officers in different giant cities, like New York and Chicago, indicated earlier this week that they didn’t plan to vary their steering on masks.

On Tuesday, Dr. Anthony S. Fauci, the federal government’s high infectious illness professional, stated on CNN that he was notably involved concerning the Delta variant inflicting outbreaks in states, cities and counties with low vaccination charges.

“It’s virtually prefer it’s going to be two Americas,” he stated, noting that areas the place comparatively fewer individuals are absolutely vaccinated — as is the case in many parts of the South — are way more in danger than areas with excessive inoculation charges.

“If you’re vaccinated, you diminish dramatically your danger of getting contaminated and much more dramatically your danger of getting severely in poor health,” Dr. Fauci stated. “If you’re not vaccinated, you might be at appreciable danger.”

Dr. Vivek Murthy, the USA surgeon basic, stated on CNN on Wednesday morning that he noticed nothing unsuitable with native authorities imposing new restrictions in the event that they appeared needed.

“If I used to be in a neighborhood that had a low vaccination charge, as quite a few our communities do across the nation, if I used to be seeing an increase within the Delta variant, I feel it’s completely affordable to consider completely different approaches we might take to restrict unfold to attempt to get forward of it,” Dr. Murthy stated.