As COVID-19 vaccination rates continue to fall, several states have spent millions of dollars on lottery prizes to encourage unvaccinated Americans to get their shot.
The million-dollar question: do they work?
Public health experts say while lotteries may nudge some people to get vaccinated most won't be convinced.
The small chance of winning a big windfall isn't enough to sway the majority of unvaccinated Americans who strongly oppose the vaccine, have safety concerns or don't want their daily lives disrupted by the vaccine's side effects, they say.
"For certain segments of the population, (lotteries) can be useful," said Robert Bednarczyk, associate professor of global health and epidemiology at Rollins School of Public Health at Emory University. "But it really comes down to, who are you trying to reach and how can you reach them."
Some states already have declared their vaccination lotteries a success.
The California Department of Public Health said the state saw a 33% increase in vaccinations after announcing "Vax for the Win," administering an average of 121,000 doses each day the first week of the program and about 161,000 daily doses the following week.
Nearly 3.5 million Ohioans entered the state's "Vax-a-Million" drawing to win one of five $1 million prizes. Ohio Gov. Mike DeWine called it "a resounding success," citing a 44% increase a week after its launch. But a recent study suggests the governor's office may have been premature in declaring victory.
Researchers at Boston University School of Medicine found Ohio's lottery did not increase COVID-19 vaccination rates when compared to other states without lottery-based incentive systems, according to the study published Friday in JAMA Network.
"When we heard the early reports that the lottery worked, we were a little skeptical," said lead author Dr. Allan J. Walkey, professor of medicine at Boston University School of Medicine and physician at Boston Medical Center.
Using data from the Centers for Disease Control and Prevention, study authors examined adult vaccination rates in Ohio four weeks before and after the lottery was announced and compared them with rates in states across the U.S.
While the decline in Ohio's vaccination rates slowed after the lottery announcement, it slowed even more in other U.S. states during the same timeframe.
"Ohio was following the same trends as the rest of the country," Walkey said.
DeWine's press secretary Dan Tierney told USA TODAY the study is flawed because it used CDC data that reflects when dose administrations were reported, not when they were given.
"Our data does not reflect the continued decline the BU study graphs claim to show," he said. "We believe the Ohio data based upon first dose start date is the most accurate measure, and that data clearly shows a significant increase after the 'Vax-a-Million' announcement."
The study also didn't include vaccination rates among 16- and 17-year-olds, who were eligible for a scholarship lottery under the same program.
Walkey, the study's author, argues other factors may have increased the state's vaccination rates.
A few days before Ohio announced its lottery on May 12, the Food and Drug Administration expanded authorization of Pfizer's COVID-19 vaccine to include adolescents over 12 years old. Walkey said the FDA's action - not the lottery - may have slightly increased vaccination rates in Ohio and other parts of the U.S.
Although researchers only looked at vaccination rates among those over 18, Walkey says adults may been more motivated to get their shots after younger teens became eligible.
"There's something potentially to that," said Bednarczyk, who was not affiliated with the BU study. "If (teens) are advocating for themselves that may have the effect of pulling their parents along with them or it may turn into a family type of thing like, 'We can all get vaccinated together.'"
The study is a "good initial look at the data," but he says more research is needed to determine if lotteries are successful at increasing COVID-19 vaccinations. The study may be masking the success of Ohio's lottery program at the hyper-local level.
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"When we look at these types of big picture studies trying to look at overall vaccination rates in a state, it's tough to really understand what's happening because even within the population of a state there may be some pockets of individuals that are more motivated," Bednarczyk said.
The same data from the CDC and local health departments also could be telling a different story depending on how it is analyzed, said Rebecca Ortiz, assistant professor at Syracuse University's S.I. Newhouse School of Public Communications.
"It all depends on how you look at the data. That's been a struggle we've been having throughout all this," she said. "You can look at the same exact data and analyze it differently and get different results, and that's not wrong."
Multiple other states followed Ohio's lead and implemented lotteries to encourage COVID-19 vaccinations, including Louisiana, Maryland, New York, New Mexico and West Virginia.
State lotteries that offer different tiers of cash prizes, gift cards and amusement park tickets - like California - may entice people more than one large cash prize like Ohio's lottery, Bednarczyk said.
While the odds of drawing one of the five winning tickets were better than winning the Powerball, experts told WDTN-TV, Ohioans were still more likely to be struck by lightning.
"If you're looking at a state of 10 million-plus people and you're giving away potentially five wining lottery draws, people may not see that as much motivation," Bednarczyk said. "Their chances are so low that the chance to win a big prize may not be enough to push people."
A better option may be to give a small prize to every person who gets vaccinated, Ortiz added.
However, prizes alone won't convince the remaining unvaccinated Americans to get their COVID-19 shot. They must be coupled with traditional public health strategies that incorporate community leaders, county health departments, education, and consistent outreach, experts say.
"Where lotteries might work best is a situation where there are lots of people on the fence who don't have strong feelings about the vaccine," Walkey said. "Lots of people are not like that … and a small chance of winning money is probably not the type of incentive that's going to change people with very strong vaccine beliefs."
Contributing: Associated Press. Follow Adrianna Rodriguez on Twitter: @AdriannaUSAT.
Health and patient safety coverage at USA TODAY is made possible in part by a grant from the Masimo Foundation for Ethics, Innovation and Competition in Healthcare. The Masimo Foundation does not provide editorial input.
This article originally appeared on USA TODAY: COVID: Ohio 'Vax-a-Million' lottery may not have worked, study says