Director of the Centers for Disease Control and Prevention Dr. Rochelle Walensky is encouraging vaccinated people looking for guidance about wearing a mask in public to follow local policies.
Walensky spoke with TODAY co-anchor Savannah Guthrie on Wednesday to address confusion over masks after World Health Organization officials last week urged fully vaccinated people to continue to wear masks and social distance, citing the rapid spread of the highly transmissible delta variant.
"We know that the WHO has to make guidelines and provide information to the world," Walensky told Savannah. "Right now, we know as we look across the globe that less than 15% of people around the world have been vaccinated, and many of those people have only received one dose of a two-dose vaccine. There are places around the world that are surging, and so as the WHO makes those recommendations, they do so in that context."
In the U.S., however, two-thirds of the adult population has been vaccinated. As of Tuesday, NBC News reported the delta variant comprised about 26% of the nation's COVID-19 cases. Los Angeles County, the most populous in the U.S., also issued a similar recommendation to WHO's on Monday.
Walensky added that the fully vaccinated adult population is "really quite protected from the variants that we have circulating here in the United States. That said, we've always said that local policymakers need to make policies for their local environment. There are areas of this country where ... they have low vaccination rates, and there are areas that have more disease. ... So in those areas, we have always said please look, make suggestions."
She then stressed that "masking policies are not to protect the vaccinated. They're to protect the unvaccinated."
Asked if the CDC's bottom line is still that if you're fully vaccinated, you don't have to wear a mask, Walensky replied, "That's exactly right."
"If you're vaccinated, you're safe from the variants that are circulating here in the United States. We would suggest that you look to your local policies because we would like our policymakers, even if you're one of the one-third of people vaccinated in their area, to adhere to the policies that are made to protect the unvaccinated."
"And then of course, as we have always said, if you have an immunocompromised condition, if you might have had a transplant and you're vaccinated, everybody should consider their own situation if they would feel more comfortable wearing a mask."
Walensky also weighed in on whether the three vaccines currently available in the U.S. — Johnson & Johnson's single-dose and Moderna and Pfizer-BioNTech's two-dose — will require booster shots, especially in light of the delta variant, which also may cause more severe disease. Research has shown that Pfizer and Moderna are quite effective against the delta variant, but Johnson & Johnson's effectiveness is still being studied.
"Right now, we have no information to suggest that you need a second shot after J & J, even with the Delta variant," Walensky said. "We have seen less data with J & J and the delta variant, and those data are forthcoming."
"However, we have every reason to believe based on how J&J is performing with other variants of concern and how its sister vaccine, AstraZeneca, has performed against the delta variant in other countries, which has done quite well ... that the J&J will perform well against the delta variant, as it has so far against other variants."
For people who are interested in receiving an extra dose of a vaccine, she explained that there's not much data available on whether doing so is effective or will lead to side effects, so she suggested participating in a study to help public health officials learn more.
The delta variant, which was first detected in India, where it drove massive surges of COVID-19, could be the dominant strain in the U.S. by fall, especially in parts of the country with low vaccination rates.