Massachusetts Rep. Ayanna Pressley attends a news conference on the FIX Clemency Act outside the US Capitol on Friday, December 10, 2021.
CNN  — 

Rep. Ayanna Pressley, a Massachusetts Democrat, announced Friday she tested positive for Covid-19 and is experiencing mild symptoms.

“After experiencing Covid-like symptoms, this morning I received a positive, breakthrough Covid-19 test result,” Pressley said in a statement. “Thankfully, my symptoms are relatively mild, and I am grateful to be fully vaccinated and boosted. I am currently isolating and following all health protocols in order to mitigate further spread and keep my loved ones and community safe.”

In her statement, Pressley also underscored “vaccines save lives” and they “are safe and effective.”

“I encourage everyone to do their part by getting vaccinated, boosted and masking up,” she continued.

Several other federal lawmakers have tested positive for Covid-19 over the last two weeks, including Massachusetts Sen. Elizabeth Warren, New Jersey Sen. Cory Booker, Delaware Sen. Chris Coons, Colorado Rep. Jason Crow, New Jersey Rep. Bill Pascrell, Illinois Rep. Bobby Rush and New York Rep. Nicole Malliotakis.

The emergence of breakthrough cases among members of Congress comes as the Omicron variant of Covid-19 has become the dominant variant in the United States, creating new challenges for the country as the pandemic moves into its third year.

The US reached a seven-day average of 254,496 new cases on Tuesday, the highest this number has ever been over the course of the pandemic, according to data from Johns Hopkins University.

That number beat the previous record of 251,989 new cases, set on January 11, 2021.

Data published Thursday by the US Centers for Disease Control and Prevention show 62% of the total US population, or more than 205 million people, are fully vaccinated against Covid-19. More than 68.8 million people have received an additional dose, or booster.

CNN’s Virginia Langmaid contributed to this report.