3 Democratic lawmakers say they've tested positive for COVID-19

Two other Democratic lawmakers joined Sen. Elizabeth Warren in announcing COVID-19 diagnoses on Sunday.

Sen. Cory Booker of New Jersey and Rep. Jason Crow of Colorado both tweeted Sunday that they had also tested positive for the virus.

Like Warren, Booker and Crow noted that they were fully vaccinated and recently got a booster shot.

Both Booker and Crow said they were only experiencing "mild" symptoms.

"I learned today that I tested positive for COVID-19 after first feeling symptoms on Saturday," Booker tweeted Sunday. "My symptoms are relatively mild. I'm beyond grateful to have received two doses of vaccine and, more recently, a booster – I'm certain that without them I would be doing much worse."

"I just returned from an official congressional delegation visit to Ukraine and tested positive for a breakthrough COVID infection," Crow tweeted "I'm thankful to be fully vaccinated and boosted and experiencing only mild symptoms (the vaccine is safe and effective)."

The announcements come as COVID-19 cases are on the rise across the country. Health experts say a small but growing number of those cases were caused by the omicron variant — a much more contagious strain of the disease that scientists say is evading vaccines at a higher rate.

However, top health experts like Dr. Anthony Fauci say that vaccines still provide adequate protection against omicron and still do an exceptional job of preventing severe infection and death.