Joe Biden accidentally referred to Kamala Harris as “president-elect” while speaking about the coronavirus pandemic.
Speaking on Tuesday, the president-elect said he and vice president-elect Harris had taken Covid-19 vaccines publically to “instill confidence” in them, when he misspoke.
Ms Harris had received her vaccine dose publicly some hours earlier, as American lawmakers and officials try to build public trust in the vaccine programme.
“I took it to instill confidence in the vaccine,” said Mr Biden, who was speaking from Wilmington, Delaware. He received a vaccine dose last week, also live on air.
“President-elect Harris took hers today for the same reason,” he then added, while accidentally referring to his running mate as the president-elect.
The 78-year-old has made the same mistake in the past, saying on the campaign trail several months ago that there would be a “Harris administration”.
Mr Biden, who will assume the United States presidency on 20 January, went on to warn that vaccines were being rolled-out too slowly by the Trump administration.
And at the current pace, said the president-elect, “it’s gonna take years, not months, to vaccinate the American people.”
“As I long feared and warned the effort to distribute and administer the vaccine is not progressing as it should,” he added, while warning that “things will get worse before they get better”.
According to the Centers for Disease Control and Prevention (CDC) on Tuesday, around 11.4 million vaccine doses have been distributed.