Associated Press

WASHINGTON — President Joe Biden on Tuesday set a new vaccination goal to deliver at least one shot to 70% of adult Americans by July Fourth as he tackles the vexing problem of winning over the “doubters” and those unmotivated to get inoculated.

Demand for vaccines has dropped off markedly nationwide, with some states leaving more than half their available doses unordered. Biden called for states to make vaccines available on a walk-in basis and he will direct many pharmacies to do likewise.

His administration for the first time also is moving to shift doses from states with weaker demand to areas with stronger interest in the shots.

“You do need to get vaccinated,” Biden said from the White House. “Even if your chance of getting seriously ill is low, why take the risk? It could save your life or the lives of somebody you love.”

Biden’s goal equates to delivering at least the first shot to 181 million adults and fully vaccinating 160 million. It’s a tacit acknowledgment of the declining interest in shots.

Already more than 56% of American adults have received at least one dose of a COVID-19 vaccine and nearly 105 million are fully vaccinated. The U.S. is currently administering first doses at a rate of about 965,000 per day — half the rate of three weeks ago, but almost twice as fa