• BA.2 now represents of 86% of sequenced new cases, almost completely displacing the earlier version of omicron that fueled the unprecedented winter surge.
• The U.S. reported more than 30,000 new infections on Monday, a 20% increase over the previous week, according to data from the Centers for Disease Control and Prevention.
• Outbreaks in New York City and Washington, D.C., have resulted in senior government officials testing positive.
• White House chief medical advisor Dr. Anthony Fauci he doesn't expect the U.S. to see a significant increase in hospitalizations and deaths.

Covid infections are rising again in the U.S. with outbreaks in New York City and Washington, D.C., resulting in senior government officials coming down with the virus as the more contagious omicron BA.2 subvariant sweeps across the country.

BA.2 now represents of 86% of sequenced new cases, almost completely displacing the earlier version of omicron that fueled the unprecedented winter surge, according to Covid surveillance data published Tuesday by the Centers for Disease Control and Prevention. The BA.2 subvariant is anywhere from 30% to 80% more transmissible than the earlier omicron variant, BA.1, according to studies from the U.K. and Denmark.

The U.S. reported more than 30,000 new infections on Monday, a 20% increase over the previous week, according to data from the CDC. However, infections and hospitalization are still more than 90% below the peak of the omicron surge in January.

Though infections are rising, most counties still have low levels of Covid transmission and hospitalizations, which means people who live in those areas don't need to wear masks indoors under CDC public health guidance. White House chief medical advisor Dr. Anthony Fauci said this week that Covid will continue to circulate in communities for the foreseeable future, and people will have to make individual decisions about the risk they're willing to take based on their age and health status.

"What we're hoping happens, and I believe it will, is that you won't see a concomitant comparable increase in severity in the sense of people requiring hospitalizations and deaths," Fauci told the ABC program "This Week." CDC Director Dr. Rochelle Walensky has previously said there's a high enough level of immunity in the U.S. population from vaccines and prior infections to provide some protection against BA.2.

The BA.2 subvariant is even more dominant in the Northeast, where it's driving a significant outbreak. BA.2 represents 92% of new cases in the region that includes New York and New Jersey, according to the CDC data. New York City reported about 1,887 new infections a day on average as of Saturday, a 52% increase over the past two weeks, according to data from the city's health department.

New York City Mayor Eric Adams tested positive for the virus on Sunday after waking up with a raspy voice. Adams attended the Gridiron Dinner in Washington, an annual event that brings together prominent government officials and journalists. At least 80 people who attended the dinner, the first since 2019, have tested positive for Covid including several senior government officials, according to Gridiron Club President Tom DeFrank.

Attorney General Merrick Garland, Commerce Secretary Gina Raimondo, Reps. Joaquin Castro and Adam Schiff, and Sen. Susan Collins all tested positive after attending the dinner.

House Speaker Nancy Pelosi, D- Calif., also tested positive for Covid last week but wasn't experiencing any symptoms and didn't attend the Gridiron Dinner. Pelosi's positive result came a day after she stood next to President Joe Biden at a bill-signing ceremony. Biden, who also did not attend the Gridiron Dinner, subsequently tested negative for Covid.

The outbreak among White House Cabinet officials and senior lawmakers comes as the rate of Covid infections in Washington has increased 73% in two weeks, though the overall level of transmission remains low compared with the winter surge. BA.2 represents 84% of new cases in the mid-Atlantic region that includes the nation's capital.

Philadelphia, meanwhile, became the first first major city in the U.S. to reinstate its indoor mask mandate effective April 18. The city made the decision after Covid cases rose more than 50% in 10 days, according to Dr. Cheryl Bettigole, Philadelphia's health commissioner.

Clarification: This story has been updated to reflect the most current data.