United Airlines is offering customers who've received COVID-19 vaccines the chance to win free flights for a year.

United Airlines is offering customers who've received COVID-19 vaccines the chance to win free flights for a year. / AP

Updated May 25, 2021 at 3:35 PM ET

Krispy Kreme is giving away a complimentary glazed doughnut to anyone who flashes their vaccine card. Maine is furnishing L.L.Bean gift certificates and free fishing and hunting licenses to residents who get the shot.

Now, United Airlines has become the latest entity to offer an incentive to get more of its customers inoculated against the coronavirus: the chance to win free flights for a year.

Companies and state governments have been rolling out inducements to the as-yet-unvaccinated in an effort to inoculate more people against the coronavirus, which has killed more than 590,000 in the U.S. alone.

The offers are aimed at overcoming vaccine hesitancy and have become more common in recent weeks as vaccine interest has slowed nationwide. A CNN poll in April found that 26% of Americans said they would not get the COVID-19 vaccine.

To enter United's contest, travelers who are part of the airline's MileagePlus program must enter a photo of their vaccine card online by June 22. United will choose five winners to receive a year of free flights — 26 round-trip tickets — in any class for themselves and one traveling companion. Another 30 flyers will be chosen to win one round-trip flight for two.

"With more dream destinations reopening for travel (ciao, Roma!), your COVID-19 vaccine is your ticket to the world," the United promotion reads.

When it comes to convincing people to get vaccinated, there is evidence the carrot works better than the stick.

Roughly a third of respondents in a recent survey by UCLA's Covid-19 Health and Politics Project said a monetary incentive would make them more likely to get the shot.

In Ohio, interest in the vaccine appears to have exploded this month after state officials created the Ohio Vax-a-Million sweepstakes, a $1 million lottery open to state residents who've received at least one shot of a COVID-19 vaccine. The state Department of Health reported a 28% increase in vaccinations the weekend after the drawing was announced.

Colorado is following in Ohio's footsteps with weekly million-dollar drawings on June 4 through July 7.

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Tags: COVID-19 vaccine  United Airlines  Series: The Coronavirus Crisis