Sen. Elizabeth Warren, D-Mass., has tested positive for COVID-19, she said Sunday.
Her symptoms are "thankfully" mild, she tweeted. She's been vaccinated and got the booster shot, she said, and is grateful for the protection they provided.
She also urged everyone who's not vaccinated already to do so, since they're both safe and effective at preventing serious illness.
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Warren didn't share in her tweets any more details about where she might have contracted the virus, though she was at the U.S. Capitol this week amid Senate Democrats' push to enact President Joe Biden's Build Back Better agenda -- which Sen. Joe Manchin, D-WV, appeared to have scuttled Sunday by saying he couldn't back the $2 trillion social and environment bill.
Later Sunday, Sen. Corey Booker, D-NJ, announced he tested positive as well.
Massachusetts, like the rest of the United States, is dealing with an uptick in COVID cases. On Sunday, there were hours-long lines at least one testing site in Cambridge, where Warren lives when she's not in Washington.
Massachusetts has seen more than 100,000 confirmed breakthrough cases of COVID as of last week; new data is released by the Department of Public Health on Tuesdays.
The delta variant of the virus is thought to be driving the current surge in the U.S., though the omicron variant -- thought to be more contagious -- may be driving up infections as well.
On Sunday, top White House medical adviser Dr. Anthony Fauci said that omicron is "just raging around the world" and said the president will soon give "a stark warning of what the winter will look like" for unvaccinated Americans.
The U.S. Centers for Disease Control and Prevention still urge people to get vaccinated, despite possible breakthrough cases. On the agency's website, it answers the question of whether vaccines are still working if booster shots are necessary by noting, " COVID-19 vaccines are working well to prevent severe illness, hospitalization, and death, even against the widely circulating Delta variant," even though the vaccine may be providing reduced population against mild and moderate forms of COVID.