The Biden administration is warning Americans to take the latest COVID-19 variant, BA.5, more seriously, but its stated strategy, released Tuesday, is to keep doing more of the same — encouraging masking, testing and getting vaccinated against COVID-19 when applicable.

The BA.5 variant now makes up more than half of all cases in the United States, and the BA.4 variant makes up roughly 20 percent. The two new omicron subvariants are much more transmissible than earlier omicron subvariants, and, unlike prior variants, can evade natural immunity.

Scientists do not yet know about the clinical severity of BA.4 and BA.5 compared to omicron strains, Centers for Disease Control and Prevention Director Rochelle Walensky said during a briefing Tuesday. But they do know it’s much more transmissible. Even those previously infected by other omicron subvariants do not have much protection against these new variants.

The good news is that current antivirals also work to treat these subvariants. COVID-19 vaccines also work to prevent infection in these variants as much as they do for other omicron subvariants.

Top public health officials said they are having active conversations about making second COVID-19 booster doses available to all adults, but the final decision will fall on the decision-makers at the Food and Drug Administration and CDC. Second boosters are currently available only to those ages 50 and up.

Bivalent COVID-19 vaccines that protect against omicron specifically should be ready in early October, said White House COVID-19 Response Coordinator Ashish Jha. But if an individual receives a second booster this summer, that doesn’t bar them from getting another shot in the fall.

Many older Americans are undervaccinated, Walensky said. Only 28 percent of people older than 50 have received a second booster shot. CDC data shows those older than 50 with only one booster are four times more at risk of dying from the virus compared to those who have two booster shots, she said.

Right now, the United States is seeing about 5,100 COVID-19-related hospitalizations per day, a doubling since early May, and about 350 deaths per day, Walensky said. About 32 percent of the country is living in an area with high COVID-19 transmission, per CDC data.

Even though the new variant is spreading rapidly, public health officials repeatedly said the U.S. is able to handle this moment in the pandemic. Jha encouraged Americans to wear masks in indoor, crowded spaces and to take a COVID-19 test before attending a large gathering, such as a wedding or visiting a high-risk person, like a grandparent.

“We’re at a point in the pandemic where most COVID-19 deaths are preventable,” Jha said.