Congress, staffers and reporters are wearing masks again as Capitol Hill faces a new wave of the coronavirus despite widespread vaccinations.

Why it matters: The Delta variant is surging, and Congress is a potential petri dish for the new variant. House and Senate leaders are weighing whether to reintroduce coronavirus protocols to the Capitol. While most lawmakers have been vaccinated, they fit high-risk profiles and work in close quarters.

• Senators and representatives also have been flying around the country visiting their home districts, fundraising and campaigning.

Driving the news:Shortly after Axios scooped that a White House official and a staff member for House Speaker Nancy Pelosi (D-Calif.) both tested positive for the virus, the phones for Axios reporters blew up with congressional aides saying the problem is even more widespread on the Hill.

• The Office of the Attending Physician indicated as much, sending a letter to members Tuesday afternoon confirming "several vaccinated congressional staff members and one member of Congress have acquired infection in this circumstance."
• "The Delta variant virus has been detected in Washington, D.C., and in the Capitol buildings," attending physician Brian P. Monahan wrote.
• The letter did not instruct lawmakers to implement new protocols but urged them to stay tuned.
• Democratic leadership aides in the House and Senate told Axios that, as of now, they have no plans to make any changes.

The latest: Many people on the Hill — particularly those with family members and children too young to get vaccinated — have taken matters into their own hands.

• After weeks of not seeing a mask, multiple people in the halls of Congress have masked up again.
• Axios' Sarah Mucha also saw the longest line in recent memory at the Capitol COVID testing site.

The good news: Those who are fully vaccinated and testing positive for the virus are overwhelmingly experiencing only mild symptoms, if any at all.

• Roughly 66% of eligible Americans have gotten at least one dose of a COVID-19 vaccine, and about 57% are fully vaccinated.

The bad news: It's still unclear how successful the vaccine is in guarding against transmission, particularly the Delta variant.

• That's a huge problem for people everywhere, compounded by a crowded and enclosed environment such as the Hill.

Many vaccinated Hill aides told Axios they haven't been getting tested, even if they do experience mild symptoms, because they've assumed it's just a cold.

• And they say they expect the vaccine to protect them regardless.

What to watch: Major conservative voices have spoken out in the last 24 hours emphasizing the importance of vaccines following the Delta variant surge.

• Fox News' Sean Hannity: "I believe in the science of vaccination."
• Senate Minority Leader Mitch McConnell (R-Ky.): "These shots need to get in everybody’s arms as rapidly as possible or we’re going to be back in a situation in the fall that we don’t yearn for."
• House Minority Whip Steve Scalise (R-La.) finally got his vaccine Tuesday: "Especially with the Delta variant becoming a lot more aggressive and seeing another spike, it was a good time to do it.”