With deaths from the coronavirus nearing 200,000 in the United States, Joseph R. Biden Jr. on Wednesday assailed President Trump for playing politics with a potential coronavirus vaccine, saying he did not trust Mr. Trump to determine when a vaccine was ready for Americans.
“Let me be clear: I trust vaccines,” Mr. Biden said. “I trust scientists. But I don’t trust Donald Trump, and at this moment, the American people can’t either.”
Shortly after Mr. Biden’s speech in Wilmington, Del., Mr. Trump seemed to lend credence to the former vice president’s criticism by publicly rebuking the head of the Centers for Disease Control and Prevention for saying that widespread vaccination might not be possible until the middle of next year. Speaking during an evening briefing at the White House, the president also kept up an attack line against Mr. Biden, misleadingly accusing him of “promoting his anti-vaccine theories.”
In his speech, Mr. Biden thrust the issue of a coronavirus vaccine to center stage in the presidential race, expressing grave concern over the political pressure he said Mr. Trump was exerting over the government’s approval process and accusing him of trying to rush out a vaccine for electoral gain.
“Scientific breakthroughs don’t care about calendars any more than the virus does,” he said. “They certainly don’t adhere to election cycles. And their timing and their approval and their distribution should never, ever be distorted by political considerations. It should be determined by science and safety alone.”
Mr. Biden delivered his remarks after receiving a briefing on the coronavirus vaccine from top national health experts, including Dr. Vivek Murthy, a former surgeon general.
As Mr. Trump, eager for a political victory, continues to suggest that a vaccine could be ready before Election Day, that prospect could become a significant campaign issue in the final stretch — if it hasn’t already.
The president’s comments that one could be rolled out before Nov. 3 have unsettled health officials, who worry that Mr. Trump is creating the impression that a vaccine might not be properly vetted at a time when the public is already concerned about political interference in the approval process.
The president accused Mr. Biden last week of using the pandemic “for political gain” and falsely claimed that his opponent had “launched a public campaign” against a coronavirus vaccine.
And Senator Kamala Harris of California, Mr. Biden’s running mate, said this month that if Mr. Trump assured the nation that a vaccine was safe, she would “not take his word for it.”
Mr. Biden said Wednesday that he would personally take a vaccine if scientists said it was safe, even if it were approved under Mr. Trump’s watch. “Absolutely, do it, yes,” he said, answering a question from a reporter.
In recent days, Mr. Trump has continued to make hopeful remarks about a vaccine. During a town-hall-style event broadcast by ABC News on Tuesday night, he said that “we’re very close to having the vaccine” and hinted that one could be ready in “three weeks, four weeks.”
And during his briefing on Wednesday, Mr. Trump said a vaccine would be announced “this month, next month,” and boasted that it had been developed “in a level of time that nobody thought was possible because of what we did with our F.D.A. in terms of streamlining it.”
Mr. Trump’s timeline has confounded many health experts, however, including Dr. Robert R. Redfield, the director of the C.D.C., who estimated during a Senate hearing on Wednesday that a vaccine could be available for limited use by the end of the year, and for wider distribution by the middle of next year. In his briefing, Mr. Trump publicly undermined Dr. Redfield, saying he thought the director had “made a mistake when he said that.”
“It’s just incorrect information,” Mr. Trump continued. “I called him and he didn’t tell me that and I think he got the message maybe confused.”
More than 30 possible coronavirus vaccines are now being tested in people, with three vaccines in late-stage clinical trials in the United States.
During his speech on Wednesday, Mr. Biden again denounced Mr. Trump’s handling of the pandemic, in what has become one of his most pointed attacks of the general election campaign. Asserting that Mr. Trump “still doesn’t have a plan to bring us out of this crisis,” Mr. Biden warned that the outbreak would continue to get worse.
“It won’t go away like a miracle,” Mr. Biden said, adding that even if a vaccine became available, it would not be available for most Americans until “well into” 2021.
“We’re heading into a very dangerous autumn,” Mr. Biden said, citing a model that projected that numbers of cases and deaths would begin to rise in November.
Asked by a reporter how he would carry out a national mask mandate, which he has previously supported, Mr. Biden said he believed he would have the legal authority as president to enforce one.
“Our legal team thinks I can do that based upon the degree to which there’s a crisis in those states, and how bad things are for the country and if we don’t do it, what happens,” he said. If it were determined that he had the legal authority to sign an executive order mandating masks, he said, he would.
Virginia Hughes contributed reporting.