BOSTON (AP) — U.S. Sen. Elizabeth Warren has tested positive for COVID-19. The Massachusetts Democrat tweeted Sunday that she’s vaccinated, has received her booster shot, and is experiencing mild symptoms in a breakthrough case of the virus.

She also used the occasion to urge anyone not vaccinated to do so.

Warren didn’t elaborate more on where she might have contracted the virus but said she tested negative for COVID earlier this week. Warren was at the U.S. Capitol last week along with other Senators as Democrats seek to pass President Joe Biden’s $2-trillion Build Back Better social and environment bill.