(The Post Millennial) – On Sunday, Senator Elizabeth Warren (D-MA), who is fully vaccinated and received the booster, announced that she has tested positive for COVID-19.

Warren announced the news on her Twitter account.

“I regularly test for COVID & while I tested negative earlier this week, today I tested positive with a breakthrough case,” the Massachusetts Democrat wrote. “Thankfully, I am only experiencing mild symptoms & am grateful for the protection provided against serious illness that comes from being vaccinated & boosted.”

“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,” Warren added in the Twitter thread.

Warren’s announcement comes as the Omicron variant continues to spread across the United States at an increasing rate.

“The cases are going up,” Dr. Anthony Fauci said last week, according to Fox News. “We have an average of about 117,000 cases. We have an increase in the percentage of hospitalizations. Deaths are still over a thousand. Then you have, looking over your shoulder, the Omicron variant, which we know, from what’s going on in South Africa and in the UK, is a highly transmissible virus.”

“That’s the reason why we are encouraging people, if they haven’t been vaccinated, to get vaccinated but, as importantly, for those who’ve been fully vaccinated to get a booster,” he continued.

In a speech he gave last week, President Joe Biden also stressed the importance of getting a booster dose. “But, there’s good news. If you’re vaccinated, you have your booster shot, you’re protected from severe illness and death period,” said Biden.

“Number two, booster shots work. Three, boosters are free, safe, and convenient. About 60 million people have one, have been boosted. So go get your shot today. Go get boosted if you had your first two shots, if you haven’t, you’ll get your first shot. It’s time it’s time, it’s past time,” Biden continued.

“We’re going to protect our economic recovery if we do this. We’re going to keep schools and businesses open if we do this, and I want to see everyone around enjoy that,” said Biden. “I want to see them enjoy the fact that you’re able to be in school, the business are open and the holidays are coming.”

Biden also reportedly plans to deliver a speech Tuesday, which will include an announcement of new COVID-19 measures to address the “new phase of the pandemic” but also “a stark warning” to unvaccinated Americans.

During a Wednesday meeting with members of the White House COVID-19 Response Team, the president warned the unvaccinated that they’re in for a “winter of severe illness and death” as the Omicron variant continues to spread.

“For unvaccinated, we are looking at a winter of severe illness and death, for unvaccinated. For themselves, their families, and the hospitals they’ll soon overwhelm,” Biden said to unvaccinated Americans.