Biden's 1st 100 days live updates: Senate passes COVID relief bill along party lines

On Wednesday, as Congress heard about serious problems on Jan. 6 regarding the security situation at the Capitol, Senate Majority Leader Chuck Schumer announced that an Army veteran, Retired Army Lt. Gen. Karen Gibson, with extensive intelligence experience will take over as the new Senate Sergeant at Arms.

Schumer unveiled an all-female leadership team heading the Sergeant at Arms office, the office that oversees security at the Capitol.

-ABC News' Trish Turner

Biden on Wednesday told reporters in the Oval Office that decisions by the Texas Gov. Greg Abbott and Mississippi Gov. Tate Reeves to relax COVID-19 restrictions by opening businesses and repealing mask mandates are a "big mistake."

"I think it's a big mistake. Look, I hope everybody has realized by now these masks make a difference," Biden said "We are on the cusp of being able to fundamentally change the nature of this disease because of the way we are able to get vaccine in people’s arms."

Despite the promising increase in vaccinations, Biden said it is not time to relax social distancing measures before enough Americans get the vaccine.

"And the last thing, the last thing we need is the neanderthal thinking that in the meantime everything’s fine, take off your mask, forget it," Biden said. "It still matters."

Biden noted that more than 500,00 Americans have died from the pandemic, saying he keeps a card with that number.

"And it’s critical, critical, critical, critical that they follow the science. Wash your hands. Hot water. Do it frequently. Wear a mask and stay socially distanced. And, I know you all know that," Biden said. "I wish the heck some of our elected officials knew it."

Biden hosted a meeting with bipartisan lawmakers Wednesday afternoon to discuss ways to get to their shared goal of ending cancer "as we know it."

"And what I want to talk with them about today is how we go about taking advantage of the work they’ve done to get us where we are today, because I think we're on the cusp of some real breakthroughs across the board on cancer," Biden said before the meeting.

White House press secretary Jen Psaki previewed the meeting, saying that fighting cancer has "significant personal importance" to Biden, whose oldest son Beau passed away after fighting brain cancer in 2015. During his tenure as vice president, Biden was tapped by former President Barack Obama to lead the fight against cancer.

First lady Jill Biden and newly sworn-in Secretary of Education Miguel Cardona visited Benjamin Franklin Elementary School in Meriden, Connecticut, on Wednesday, to see how the school was adapting to the pandemic. Biden began the tour in a kindergarten classroom, where a teacher at the school showed her plexiglass dividers with pool noodles on the edge, one of the mitigation strategies.

On the next stop on the tour, the first lady visited a sensory room to learn how they modified their approach for special needs students, as well a second-grade classroom, though no students were present.

“I think the teachers are doing such a great job in, you know, meeting the kids where they are, whether that’s in school, whether it’s at home. I mean, really, I think what the teachers have done here to help...America’s children has just been incredible,” Biden said.

-ABC News' Molly Nagle