The Biden administration, in a final push to shore up the nation’s pandemic preparedness before President-elect Donald J. Trump takes office, announced on Thursday that it would nearly double the amount of money it was committing to ward off a potential outbreak of bird flu in humans.

Federal health officials have been keeping a close eye on H5N1, a strain of avian influenza that is highly contagious and lethal to chickens, and has spread to cattle. The virus has not yet demonstrated that it can spread efficiently among people.