U.S. officials have scaled back many indoor mask mandates and vaccine requirements, marking the shift to treating COVID-19 as endemic.

But White House advisors are warning that COVID cases will likely rise again because of the BA.2 Omicron subvariant spreading through the U.S..

“The bottom line is we likely will see an uptick in cases, as we’ve seen in the European countries, particularly the U.K.,” said Anthony Fauci, the chief White House medical adviser, in a March 20 appearance on ABC’s This Week.

BA.2 cases on the rise

Known as “stealth Omicron,” the BA.2 subvariant has a different genetic sequence from BA.1, its Omicron predecessor. That difference makes it harder to detect and classify in current PCR tests, according to the U.K. Health Security Agency.

BA.2 is about 50% more transmissible than the original Omicron strain. But it doesn’t cause more severe illness, evade vaccinations, or cause earlier infection, according to Fauci.

The strain’s increased transmissibility has already contributed to a steady rise in cases in the U.K. and other parts of Europe recently.

In the U.S., BA.2 currently accounts for about 30% of infections, up from just 14% the week before, according to the U.S. Centers for Disease Control and Prevention. At the current pace, it could become the dominant coronavirus strain in the coming weeks.

Even if BA.2 continues to cause increases in U.S. case totals, Fauci said he’s hopeful it won’t correlate to a new rise in hospitalizations or deaths, which have been consistently lower since the initial Omicron strain peaked in late January.

“Hopefully we won’t see a surge [like we did with previous variants]. I don’t think we will,” Fauci said.

S. Surgeon General Vivek Murthy echoed Fauci’s comments in an appearance on Fox News Sunday, noting that the U.S. is better prepared to handle a new spike in cases because of vaccines. Murthy said he does not expect the impact of BA.2 to be as severe as previous waves.

“We should be prepared; COVID hasn’t gone away,” Murthy said on March 20. “Our focus should be on preparation, not on panic.”

A lack of funding from D.C.

The emergence of BA.2 in the U.S. comes as Congress stalls passing legislation that would allocate an additional $15 billion in pandemic funding that the White House says will be necessary to combat the virus.

Until more funding is secured, the U.S. government will run out of supplies of COVID treatments like antiviral pills and monoclonal antibodies as soon as May, according to Reuters.

"With cases rising abroad, scientific and medical experts have been clear that in the next couple of months there could be increasing cases of COVID-19 in the United States as well," White House Press Secretary Jen Psaki told reporters last week.

"Waiting to provide funding until we're in a worse spot with the virus will be too late,” Psaki added. “We need funding now so we're prepared for whatever comes."