Joe Biden has promised to distribute “100 million shots” of vaccine in the “first 100 days” of his presidency.
Mr Biden, who will take over as US president from Donald Trump in January, was speaking as he introduced his pandemic response team.
He said that Americans should wear masks for 100 days to prevent the coronavirus from spreading and that he would make this mandatory on public transport and in federal buildings.
“In 100 days, we can change the course of the disease and change life in America for the better,” he said, adding: “Whatever your politics or point of view, mask up for 100 days.”
Mr Biden also said he believed the virus could be well enough under control to allow the “majority” of schools to be reopened during his first 100 days as president.
He said: “My first 100 days won’t end the COVID-19 virus. I can’t promise that.
“But we did not get into this mess quickly. We’re not going to get out of it quickly. It’s going to take some time.”
The number of US deaths from the coronavirus has soared to an average of more than 2,200 a day, matching the peak seen in April.
More than 283,000 people have died with the virus in the US and the average number of daily cases has passed 200,000 for the first time.
US President Donald Trump has signed an executive order to ensure preferential vaccine access for his country
Meanwhile, Mr Trump threatened to use the Defense Production Act to make sure Americans are first in line for US-produced coronavirus vaccines.
The US president was speaking at a summit on vaccine development and distribution, where he signed an executive order to ensure vaccines procured by the US are used there before they are sent anywhere else.
The Defense Production Act was passed in 1950 and allows the president to expand industrial production of key materials or products for national security.
Mr Trump said: “If necessary… we’ll invoke the Defense Production Act, but we don’t think it will be necessary.
“If it is, it’s a very powerful act, as you know, because we’ve used it very, very successfully.”
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Mr Biden’s team was not invited to the summit, despite the fact that they will be handling most of the vaccine distribution effort.
Mr Trump, meanwhile, appeared to be still struggling with the fact that he had lost November’s election.
When asked why none of Mr Biden’s team had been invited, he said: “We’re going to have to see who the next administration is, because we won in those swing states and there was terrible things that went on. But whichever the next administration is will really benefit by what we have been able to do.
“Hopefully the next administration will be the Trump administration.”
The US has not yet given the go ahead for the widespread use of a coronavirus vaccine, but the jab from Pfizer – the one that has been rolled out in the UK – is expected to be approved this week.