Biden responded to concerns that another shutdown could harm the economy, already hurting from closures caused by the pandemic.

"I'm going to shut down the virus, not the country," he said. "It's his ineptitude that caused the virus -- caused the country to have to shut down in large part. Why businesses have gone under, why schools are closed, why so many people have lost their living and why they're concerned."

After attacking Trump for golfing during the pandemic, Biden said he hadn't ruled out additional shutdowns if necessary.

"You need standards," he said. "The standard is if you have a reproduction rate in a community that's above a certain level, everybody says slow up. More social distancing. Do not open bars and do not open gymnasiums."

In rebuttal, Trump criticized Democratic governors in several states for shutting down in response to the pandemic.

"They're shut down so tight and they're dying," he said. "They're dying. And he supports all these people. All he talks about is shutdowns. No, we're not going to shut down. And we have to open our schools."

In an example of how young people have better outcomes with coronavirus, the president mentioned his son Baron who tested positive.

"By the time I spoke to the doctor the second time, he was fine. It just went away. Young people -- I guess it's their immune system," he said.

Trump and Biden have contradictory views on the president's handling of the pandemic with Trump asserting he's done better than any other world leader and Biden claiming he's done "virtually nothing."

Trump's insisted again that the pandemic is "going away," touting his administration's efforts on therapeutics and vaccines.

"I don't think we're gonna have a dark winter at all," Trump said. "I say we're learning to live with it. We have no choice. We can't lock ourselves up in a basement like Joe does," drawing a laugh from Biden.

Biden emphasized the lives already lost, making a direct appeal to those at home.

"Number one, he says that we're, you know, we're learning to live with it. People are learning to die with it," Biden said. "You folks home who have an empty chair at the kitchen table this morning, that man or wife going to bed tonight and reaching over to try to touch their -- out of habit where their wife or husband was is gone. Learning to live with it? Come on."

When Trump threatened that Biden would shutdown the country if elected, causing massive economic depression, Biden said, "I'm going to shut down the virus, not the country."

In response to a question on how he would lead the country out of the crisis caused by the COVID-19 pandemic, Biden cited the more than 220,000 Americans who had died from the virus.

"Anyone who's responsible for that many deaths should not remain as president of the United States of America," he said.

Biden went on to say that Trump doesn't have a plan for dealing with the virus. He called for mask wearing, and a national policy on mask wearing, more testing and a national policy on reopening schools and businesses.

"I will take care of this. I will end this," Biden said to close out his first answer. "I will make sure we have a plan."

Trump tackled the first question on the coronavirus pandemic but stuck to his stance the pandemic is "rounding the corner" and "going away."

"Since the two of you last shared a stage, 16,000 Americans have died from COVID," Welker said. "So please be specific, how would you lead the country during this next stage of the coronavirus crisis?"

"As you know, 2.2 million people modelled out were expected to die," Trump began. "We closed up the greatest economy in the world in order to fight this horrible disease that came from China."

He went on to draw from his personal experience contracting COVID-19, downplaying its side effects and touting the country's therapeutics.

"I can tell you from personal experience that I was in the hospital. I had it. And I got better," Trump said. "And I will tell you that I had something that they gave me, a therapeutic, I guess they would call it, some people could say it was a cure. But I was in for a short period of time and I got better very fast or I wouldn't be here tonight. And now they say I'm immune. Whether it's four months or a lifetime, nobody has been able to say that, but I'm immune."

"It will go away and as I say, we're rounding the turn. We're rounding the corner. It's going away," he added.

TRUMP'S CLAIM: "The children are brought here by coyotes and lots of bad people, cartels, and they're brought here and they used to use them to get into our country." // "They built cages. You know, they used to say I built the cages." // "They are so well taken care of. They are in facilities that are so clean."

FACT CHECK: Trump was defending his now-defunct policy known as "zero tolerance" that required every adult who crossed the border illegally -- even those traveling with their children -- be detained in a bid to deter border crossings.

The result was that thousands of children were separated from their parents in a matter of weeks. It was a major departure from past U.S. policy. In the Barack Obama and George W. Bush administrations, families were separated in rare instances, such as cases of serious crimes like drug trafficking. 

Critics of Trump's policy questioned the conditions the kids were kept in initially at border stations after several died of the flu.

An internal investigation later found that the administration struggled to keep track of the parents, many of whom had been deported. The White House says the parents were contacted and abandoned the children, who were placed with U.S. sponsors, usually family members. The American Civil Liberties Union countered that parents have not been found and contacted and therefore could not give up rights to their children.

Homeland security officials have said that "coyotes" are often used to transport the families for a fee. But there has not been widespread evidence of cases of people falsely presenting themselves as related, with border patrol documenting them as "family units."

Trump's suggestion that "cages" were built by the Obama administration is correct. Obama had faced an influx of children both traveling alone and with families as a result of violence in Central America. And at one point, the Obama administration tried housing the families in special detention centers.

But after a federal judge in California ruled that the arrangement violated a long-standing agreement barring kids from jail-like settings for extended periods, even with their parents, the government began releasing families into the U.S. pending notification of their next court date.

In 2018, photos taken by The Associated Press and posted online by liberal activists suggested the children in steel fencing was Trump's doing. The photos were actually from 2014 when immigration detentions became flooded with families.

-ABC News' Anne Flaherty