The United States is confronted with an ever-growing surplus of coronavirus vaccine, looming expiration dates and stubbornly lagging demand at a time when the developing world is clamoring for doses to stem a rise in infections.

Million-dollar prizes, free beer and marijuana, raffled-off hunting rifles and countless other giveaways around the country have failed to significantly move the needle on vaccine hesitancy, raising the specter of new outbreaks.

The stockpiles are becoming more daunting each week. Oklahoma has more than 700,000 doses on shelves but is administering only 4,500 a day and has 27,000 Pfizer and Moderna doses that are set to expire at the end of the month.

“We really cannot let doses expire. That would be a real outrage, given the need to get vaccines to some under-vaccinated communities in the U.S. and the glaring gap in vaccinations and the inequity of vaccinations that we have globally,” said Dr. Kirsten Bibbins-Domingo, chair of epidemiology and biostatistics at the University of California, San Francisco.

The U.S. averaged about 870,000 new injections per day at the end of last week, down sharply from a high of about 3.3 million a day on average in mid-April, according to the Centers for Disease Control and Prevention.

President Joe Biden wants to have 70 percent of the adult U.S. population at least partially vaccinated by July 4. But the U.S. could well fail to meet that target. As of Friday, 64 percent of Americans 18 and older had had at least one dose, by the CDC’s count.

Some states, especially in the Northeast, have already reached that 70 percent goal for adults, while places like Mississippi and Alabama are nowhere close. Mississippi, in fact, has been transferring large quantities of vaccine to other states and the federal government.

Amid the glut, the White House has announced plans to share 80 million doses globally by the end of June and also buy 500 million more doses of the Pfizer vaccine and donate them to 92 lower-income countries and the African Union over the next year.

Dr. Nirav Shah, head of the Maine Center for Disease Control and Prevention and president of the Association of State and Territorial Health Officers. said the nation’s vaccine rollout is moving much more quickly than he expected, and he welcomed efforts to expand distribution to hard-pressed regions like Africa.

“One of the things that the pandemic has illustrated is that we are not safe, as a state, as a country, as a globe, until everywhere is safe,” he said. “We should be doing our part to vaccinate everyone in the globe.”