The Massachusetts Democrat, who is vaccinated and boosted, said she is experiencing mild symptoms. Warren was on the Senate floor last week before the chamber went on recess. “I regularly test for COVID & while I tested negative earlier this week, today I tested positive with a breakthrough case. Thankfully, I am only experiencing mild symptoms & am grateful for the protection provided against serious illness that comes from being vaccinated & boosted,” she tweeted. “As cases increase across the country, I urge everyone who has not already done so to get the vaccine and the booster as soon as possible – together, we can save lives.”