To get to herd immunity, Dr. Anthony Fauci, Biden’s chief medical adviser on the coronavirus pandemic, said 75 percent of Americans need to be vaccinated. In his first network interview of his presidency, Biden told Norah O’Donnell that the big sticking point to reaching that benchmark was the lack of a sufficient supply of vaccines.

The Trump administration’s handling of the pandemic was “even more dire than we thought,” Biden said.

“They had indicated there was a lot more vaccine available and it didn’t turn out to be the case,” he added.