Biden spent much of his election campaign criticising President Donald Trump's handling of the pandemic, which has now caused the deaths of 237,000 people in America.
The United States saw a record number of new infections last week, with the total number of cases nearing 10 million.
After four days of uncertainty as votes were counted in key states, Biden's victory in Pennsylvania put him over the threshold of 270 Electoral College votes he needed to clinch the presidency. Trump has not conceded and has vowed to challenge the outcome in court.
