Masks are again required for members of the House side of the U.S. Capitol amid a nationwide rise in coronavirus cases.

Under the reimplemented mandate, members, both vaccinated and unvaccinated, must wear a "well-fitted, medical grade, filtration face mask" in House office buildings, during meetings and while in the House chamber.

Under the order from Dr. Brian Monahan, Congress' attending physician, the new rule doesn't affect members of the Senate.

The return of masks in the House comes a month after the requirement was first lifted for vaccinated members.

An uptick in cases in the U.S. due to the highly contagious delta variant also led to the the Centers for Disease Control and Prevention to reverse its earlier position on face coverings. The agency said it recommends fully vaccinated people wear masks indoors if they live in areas with significant or high spread.

The delta variant is more than two times as transmissible as the original strain of the virus, according to experts. All of the vaccines have shown substantial protection against developing severe illness in people infected with the delta strain.

House Minority Leader Kevin McCarthy, R-Calif., immediately criticized efforts to mandate mask wearing again.

He tweeted, "Make no mistake—The threat of bringing masks back is not a decision based on science, but a decision conjured up by liberal government officials who want to continue to live in a perpetual pandemic state."

Members who fail to wear a mask are punishable by a fine or denial of entry into the chamber.

Republican Reps. Thomas Massie, Marjorie Taylor Greene and Ralph Norman were each fined $500 in May for refusing to wear masks.

After losing their appeals to the House Ethics Committee, the trio said this week that they are suing House Speaker Nancy Pelosi, D-Calif., over the fines, according to The Louisville Courier Journal.

White House reporters must mask up

The White House Correspondents' Association announced Tuesday, in the wake of the CDC releasing its new guidance, that it will also require reporters to wear masks while they are inside the White House.

The White House said President Biden and other fully vaccinated administration officials would abide by the CDC's new guidance and wear masks where appropriate.

Biden's chief medical adviser and the nation's top infectious disease expert, Dr. Anthony Fauci, told NPR that the dominance of the delta variant and the ease with which it spreads is the rationale behind new mask guidance.

"We are dealing with a different virus now. This is not the original virus that we were dealing with; this has different capabilities, much more efficient in transmitting from person to person," he said. "Now, the delta variant is totally dominant, it's well over 80, 85%, and in some sections of the country, it's close to or above 90%. This variant is much more capable of transmitting from people to people."

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