70-year old Biden was administered the oath of office on his family Bible by the Supreme Court Associate Justice Sonia Sotomayor at a private ceremony at his official residence here, following a private mass.
Obama and Biden are being sworn in today, January 20, the Constitutionally-mandated date for the President to be sworn in to office.
Apart from Biden's family, about 120 guests - including Attorney General Eric Holder, House Minority Leader Nancy Pelosi, and former Senator/Defence Secretary nominee Chuck Hagel watched him take the oath.
Interestingly, the Vice President's swearing in is not mentioned in the American Constitution; his oath is mandated by congressional statute.
Because it is a Sunday, however, the official inauguration ceremony will take place on Monday, with the two taking their oaths again followed by all the pomp and circumstance afforded to inaugurals.
Biden used his family's Bible for the swearing in and will use the same Bible for his swearing in on Monday.
The Bible "is five inches thick, has a Celtic cross on the cover and has been in the Biden family since 1893," the Vice President's office said.
"He used it every time he was sworn in as a US Senator and when he was sworn in as Vice President in 2009. His son Beau used it when he was sworn in as Delaware's attorney general," a White House official said.
Three women have previously sworn-in presidents and vice presidents: Judge Sarah T Hughes swore-in President Johnson in 1963; Justice Sandra Day O'Connor swore-in Vice President Dan Quayle in 1989; and Justice Ruth Bader Ginsburg swore-in Vice President Al Gore in 1997.
Washington: US Vice President Joe Biden was on Sunday officially sworn for his second term, hours before President Barack Obama takes his second oath of office at the White House.
First Published: Sunday, January 20, 2013, 21:23