The nation’s top doctor Monday urged people to elbow-bump — and sing “Happy Birthday’’ while washing their hands to draw out the cleaning ritual — to try to help prevent the spread of the coronavirus in the US.

“We cannot hermetically seal the United States,’’ US Surgeon General Jerome Adams said at a press conference in Connecticut, where he toured a virus testing lab.

“We’re encouraging communities to think about the steps they can take to limit spread within communities to mitigate the effects of the virus,’’ Adams said, citing such things as the singing while hand-washing to ensure a 20 second-or-more rinse and greeting people with an elbow-bump to avoid spreading germs through handshakes.

Adams then demonstrated the elbow-bump with US Sen. Richard Blumenthal and Conn. Gov. Ned Lamont, who were flanking him.

Former CDC Director Dr. Tom Frieden said that even fist-bumping is five times less likely to give you germs.

“We should probably rethink the handshake for a while,” he told reporters Monday.

There are no confirmed cases of the deadly bug in Connecticut, but some groups in the state are taking no chances.

The University of Connecticut said Monday that it is requiring 14 days of self-quarantining for 90 students who were brought back home from study-abroad programs in Italy and South Korea, two countries particularly hard-hit by the virus, according to the Hartford Courant.

— Additional reporting by Jackie Salo