Both senators said they are vaccinated and have had booster shots. Although contracting the coronavirus while fully vaccinated is known as a breakthrough case, both attributed their mellow experiences so far with the deadly disease to their top-level inoculation.
"I regularly test for COVID & while I tested negative earlier this week, today I tested positive with a breakthrough case," Warren, D-Mass., said on Twitter. She said she is feeling only mild symptoms and is "grateful for the protection provided against serious illness that comes from being vaccinated & boosted."
Booker, D-N.J., later tweeted that he had mild symptoms Saturday and tested positive.
"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," he said.
Late in the day a third congressional Democrat, Rep. Jason Crow of Colorado, tweeted that he has tested positive upon return from an official visit to Ukraine. He said his was also a breakthrough case.
"I’m thankful to be fully vaccinated and boosted and experiencing only mild symptoms (the vaccine is safe and effective)," Crow said.
While it appears that the omicron variant of the coronavirus, believed to be a factor in the December wave, is more contagious and may increase the chances of breakthrough infections, vaccinated people generally seem to be experiencing symptoms no worse than when other variants broke through to inoculated patients.
Neither senator identified which strain of the virus they have.
The reported number of pandemic cases in New York state on Saturday was a record. At the same time, there were 97 percent fewer hospitalizations for Covid-19 patients in New York City compared with the pandemic's last peak in 2020, NBC New York reported.
Cities and schools are bracing for a rapid rise in cases of infection with the omicron variant amid the continued onslaught of the delta variant. A growing number of schools are closing as the Biden administration unveiled a new strategy Friday to use increased Covid testing to keep children in classrooms.
Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, warned Sunday that the next few weeks will put severe stress on hospital systems as the omicron variant is "raging around the world."
There is no doubt about the omicron variant's "extraordinary capability" for transmission, Fauci said on NBC's "Meet the Press." Although the latest coronavirus mutation appears to cause less severe symptoms in vaccinated people, Fauci warned that its transmissibility counteracts the mildness of the cases.