The vice president received the first dose on live TV.
The top infectious disease expert in the US says he did not mean to “imply any sloppiness”.
“If Anthony Fauci tells me this vaccine is safe and can immunize you from getting Covid, absolutely I’ll take it," Obama said this week.
The former White House strategist said he would like to put “heads on pikes” as a "warning", in a deeply disturbing podcast message.
Harrison Ford narrates the latest video from The Lincoln Project.
"We're in for a whole lot of hurt," warned the nation's top infectious disease expert.
He told the BBC the effectiveness of coronavirus vaccine could be known before the end of this year.
The president threw face masks to the crowd, but did not wear one himself.
Currently there are entire countries with fewer active cases than the White House.
Several hospitals in the north of England are already using the experimental treatment given to the US president.