The administration's credibility on Covid-19 immediately emerged as a flashpoint during the debate, with over 211,600 U.S. deaths and more than 7.5 million infections. Harris seized on comments national security adviser Robert O’Brien made to Trump on Jan. 28, calling the coronavirus “the biggest national security threat” he’ll face in his presidency. The discussion was revealed by Washington Post associate editor Bob Woodward in a story on his book.

But Pence didn't duck the issue, saying case counts would have been worse if Trump didn’t shut down travel from China and adding the move “bought us invaluable time.”

Harris' declaration she wouldn't follow Trump's advice on a vaccine, but would if scientists endorsed it, drew a spirited response from Pence, who accused the California Democratic senator of undermining public confidence in a cure. Public health experts have repeatedly expressed concern that Trump is contributing to rising Covid-19 vaccine hesitancy, as he publicly pushes for a vaccine before Election Day.

The vice president also accused the Biden campaign of “plagiarism,” alleging the Biden campaign’s playbook to defeat the coronavirus “reads an awful lot like what President Trump and I and our task force have been doing every step of the way.”

Pence has played a central role leading the White House coronavirus task force and earning praise from state and local officials for being more attuned to their concerns than Trump or his team. But Pence’s penchant for building consensus and his focus on public perception slowed the response.

Pence attempted to deflect from the administration’s handling of the coronavirus, by bringing up Joe Biden’s response to the swine flu during the Obama administration and characterizing it as a “failure.”

“If the swine flu had been as lethal as the coronavirus in 2009, when Joe Biden was vice president, we would have lost 2 million American lives,” Pence said.

But the diseases are very different. The swine flu didn’t lead to nationwide lockdowns, massive unemployment and disease so infectious that it’s unclear when Americans will return to their normal lives.

Eight months into the pandemic, cases are still climbing by the tens of thousands. And the White House is struggling to control the spread of the virus within its own ranks less than a week after Trump tested positive. At least 34 people in Trumpworld have been infected, including press secretary Kayleigh McEnany and Stephen Miller, a senior adviser to the president.

In the lead-up to the debate, questions emerged over whether Pence should quarantine. In an attempt to quash concerns, the vice president's office released a memo from CDC Director Robert Redfield saying his agency concluded it was safe for Pence to participate “from a public health standpoint.”

Earlier this week, the two campaigns fought over whether to erect a plexiglass barrier between the candidates. Pence’s team ultimately yielded, yet some epidemiologists have questioned whether the barrier will make the candidates much safer.

For months, Democrats have viewed the pandemic as a huge weak spot for Trump. Nearly 6 in 10 Americans surveyed believe Joe Biden would handle the pandemic better than the president, according to a CNN poll conducted by independent research company SSRS and released Tuesday.