Trump administration and campaign officials faced questions Sunday over Vice President Mike Pence’s travel plans after at least five of his aides tested positive for COVID-19.

Saskia Popescu, an infectious disease expert at George Mason University, called Pence's decision to maintain his aggressive travel schedule "grossly negligent." Social media also blasted Pence for not effectively adhering to guidelines.

As Election Day just eight days away, Pence is expected to step up his travel. He has campaign stops in North Carolina, Pennsylvania and Minnesota.

On Sunday, White House chief of staff Mark Meadows defended Pence’s campaign travel on CNN’s “State of the Union,” promoting the administration’s argument that Pence serves as an essential worker and is allowed to continue campaigning in person.

"As we look at that, essential personnel, whether it's the vice president of the United States or anyone else, has to continue on,” Meadows said.

Meadows declined to say how many people in the vice president’s office have contracted coronavirus, telling CNN that “we don’t give out that kind of information.”

Meadows also added that Pence is “wearing a mask, socially distancing and when he goes up to speak he will take the mask off, put it back on.”

Pence’s chief of staff Marc Short, adviser Marty Obst, and close aide Zach Bauer all tested positive for COVID-19. The two other positive cases are still unknown. Pence, meanwhile, has twice tested negative.

Trump campaign adviser Corey Lewandowski on Sunday also stood by Pence’s campaigning in an appearance on NBC’s "Meet the Press."

While Obst has not been in recent contact with Pence, Short has been in frequent contact with the vice president.

Centers for Disease Control and Prevention guidelines instruct those who were in close contact with a person with COVID-19 to stay home for 14 days after their last contact with the individual.

Former New Jersey Gov. Chris Christie told ABC News' “This Week” on Sunday that he was surprised Pence was staying on the campaign trail after his aides' positive tests.

"I think everybody's got to put the health of the people they're going to be in touch with first," Christie said.

“You got to keep yourself away from everybody and I'm a little bit surprised," he added.

Christie previously tested positive and was hospitalized for COVID-19 for a week after attending Trump’s nomination of Judge Amy Coney Barrett to the Supreme Court.

Trump reelection campaign events with the president or vice president have gathered hundreds, usually outdoors, with the majority of the crowd not socially distancing or wearing masks.

U.S. cases of COVID-19 on Friday reached a single-day record of 85,085.

Coronavirus