When confronted by Wallace about the disparity between what his public health officials are saying and what he has said about the timing of the vaccine, Trump stuck with his previous comments.

"We can have it a lot sooner," Trump said. "It's a very political thing because people like this would rather make it political than save lives."

Top U.S. government public health officials and other experts have said that it's possible -- if everything goes well, but unlikely -- that vaccine trials will have enough clear and compelling data to be available by the end of October or beginning of November. Dr. Anthony Fauci, the nation's foremost infectious disease expert, has said he thinks there will be a "safe and effective vaccine" by "the end of this calendar year."

Fauci has also said that the United States will not return to "normal" until the middle of next year.

Biden interrupted the president by referring to Trump's previous statements earlier this year, when he said the virus would be gone by Easter and then also referenced Trump's potentially dangerous comment that people can inject bleach to get rid of the virus. Trump then responded that he said the bleach comment "sarcastically" made.

Biden turned to the hundreds of thousands of Americans who have died due to the coronavirus.

"His own head of the CDC said if we just wore masks between now -- if everybody wore masks and social distanced -- between now and January, we probably save up to 100,000 lives," Biden said.

Wallace pivoted the conversation to the global COVID-pandemic, and Biden began by listing statistics including 200,000 Americans dead and over 7 million infected.

"The president has no plan. He hasn't laid out anything. He knew all the way back in February how serious this crisis was. He knew it was a deadly disease," Biden said. "And I laid out again in July what we should be doing."

You should get out of your bunker and get out of the sand trap and your golf course and go in your Oval Office and bring together the Democrats and Republicans and fund what needs to be done now to save lives," he continued.

Trump countered by saying if the country had listened to Biden then millions of people would have died, not 200,000, and touted his decision to restrict travel from China in February, along with his efforts on ventilators and vaccine development.

"When you talk about numbers you don't know how many people died in China, you don't know how many people died in Russia, you don't know how many people died in India. They don't exactly give you a straight count," Trump said.

While on the topic of the Supreme Court and the fate of the Affordable Care Act, Trump was quick to call Biden's health care plan "socialized Biden."

Biden, notably, has said he does not support "Medicare for All" and responded by calling out Trump for promising to repeal and replace Obamacare -- which he hasn't.

"He does not have a plan," Biden said. "The fact is this man doesn't know what he's talking about."

Less than 20 minutes into the debate, both candidates have interrupted each other multiple times, making it difficult to understand what either is saying. Wallace has specifically asked Trump multiple times to let Biden finish his thought.

Eventually, the cross-talks continued for long enough that the former vice president said, "Will you shut up, man?" to the president.

ABC News Chief Anchor George Stephanopoulos called Tuesday's debate the worst he has ever seen in his life.

"I have to speak personally here, as somebody who's watched presidential debates for 40 years, as somebody who's moderated presidential debates, as someone who's prepared candidates for presidential debates, and someone who's covered presidential debates, that was the worst presidential debate I have ever seen in my life -- a lot more heat than light over some 90 minutes," he said.

ABC News Chief White House Correspondent Jonathan Karl said, "It looked as if both men lost this debate" but added that it was Trump who had more to lose.

"In that sense the real loser is Donald Trump," Karl added. "Donald Trump was the one that needed to change the dynamic of this race."

ABC News' Senior Congressional Correspondent Mary Bruce reported that the Biden's campaign is "feeling very good right now," following the debate, saying they believe every time Biden "went around the president" and spoke directly to the viewers "they were winning."