The Ohio Department of Public Health reported that more than 2.7 million adults entered its first weekly Vax-a-Million drawing for a one million dollar prize, and more than 100,000 teens entered for a college scholarship. The first winners were announced Wednesday, while entries remain open for next week’s lottery, the second out of five. The entry process is simple: get your shot, then fill out an online form.  

New York, Maryland, Colorado, and Oregon have announced plans for their own lotteries. Under New York’s “Vax and Scratch” program, people who get vaccinated at one of the state’s mass vaccination sites from May 24-28 will receive a free scratch of ticket for the $5,000,000 Mega Multiplier lottery, normally valued at $20. Maryland recently rolled out its $2 million VaxCash promotion, a series of 40 statewide drawings for $40,000. Everyone who is vaccinated is automatically enrolled. Colorado and Oregon residents are also automatically entered in their states’ respective lotteries when they receive a vaccination. Colorado will be giving away five $1 million prizes, and Oregon will hold a single lottery for prizes ranging from $10,000 to $1 million on June 27.

Similarly, some states are offering direct cash incentives. For example, under New Jersey’s “shot and a beer” program, any state resident who gets their first vaccine dose in the month of May can get a free beer at a participating brewery. Maryland is offering a direct $100 payment to state employees who receive the vaccine. And in West Virginia, 16-35 year-old residents will get a $100 savings bond for getting vaccinated.  

Some businesses, particularly restaurants, are jumping on the bandwagon, as well. Krispy Kreme was one of the first, offering a free doughnut per day to customers who present their vaccination card. White Castle is offering a free dessert to its vaccinated customers. And, if you’re vaccinated, you can get a free side of fries at Shake Shack. Companies offering financial incentives for vaccinations include Aldi, Kroger, McDonald’s, and Trader Joe’s–generally in the form of store credit or paid time off for employees. 

While increasingly popular, vaccine incentive programs have been hotly controversial from the outset. Krispy Kreme’s announcement drew swift condemnation on social media for everything from discrimination against the unvaccinated to irresponsible distribution of unhealthy food.

Meanwhile, Ohio legislators immediately got busy trying to cancel Vax-a-Million. Ohio State Rep. Jena Powell, known in the state as an opponent of vaccines generally, has sponsored a bill that would prevent the state from operating any vaccine lottery.

“The vaccine lottery is a frivolous use of taxpayer dollars,” Powell tweeted. And it’s not just Republicans opposing the lottery. Vax-a-Million drew fire from the other side of the aisle, as well. Speaking to the Cincinnati Enquirer, Ohio House Minority Leader Emilia Strong Sykes called it a “grave misuse of money that could be going to respond to this ongoing crisis.”

Despite the objectors, however, vaccine payment programs do seem to be boosting vaccination rates. Ohio reported a 53% increase in first-dose vaccinations in the first week entries were open for Vax-a-Million. And results of a recent survey of over 75,000 people from the UCLA Covid-19 Health and Politics Project, reported in the New York Times, supported the idea that cash incentives for vaccination could be very effective, at least in some cases. The survey found that about one-third of unvaccinated respondents said they would be more likely to get vaccinated in exchange for a $100 cash payment, compared to 15% who said they would be less likely–a net gain of 19%.

The Biden administration is sufficiently convinced of the value of lotteries and cash incentives for vaccinations that it’s encouraging states to offer them. In a press briefing this week, Andy Slavitt, the White House senior advisor for Covid-19 response, said that Ohio’s Vax-a-Million program is working, and noted that only nine states so far have reached the President’s goal of having 70% of all eligible adults vaccinated with at least one shot by July 4th.

Most of these incentives have a value of $100 or less per shot, but Brookings Institution economist Robert E. Litan has argued that the US should pay Americans $1,000 to get the Covid-19 vaccine, reasoning that achieving herd immunity would justify the estimated $275 billion cost. 

While the initial bump in Ohio’s vaccination numbers is encouraging, there are some indications that suggest financial incentives could be ineffective, or, in some circumstances, could even backfire by creating a perception that the vaccine is riskier than it really is. Criticisms that incentive programs are are not the best use of funds for fighting the pandemic may have a grain of truth.

According to a 2009 research paper by Cynthia Cryder, an associate professor of marketing at Washington University, clinical trials that offer payments can motivate people to participate, but that comes with a perception of increased risk.

The study looked at subjects’ attitudes toward two mock clinical trials. One was described as a trial of transcranial magnetic stimulation, and the other involved a simple blood draw. “We thought we might see different effects because one is more familiar and one is less familiar, but it looked essentially the same,” Cryder told Flux. She found, instead, that participants’ perception of risk was connected to the payment.

While it makes sense to compensate study participants for genuinely risky interventions, Cryder pointed out that the Covid-19 vaccines are low risk, and offering payment could lead to a false belief that the Covid vaccine, or vaccines in general, are high risk. “The big bottom line that’s true of any policy decisions is that they should be tested before they’re put into practice,” says Cryder. However, she noted, “The lotteries have a slightly different feel. I wonder if they get around this issue. But we don’t have data on it.”

Ethicists Emily Largent and Franklin Miller, of the University of Pennsylvania, argue that payments for vaccination are not only unnecessary, but “problematic.” Among the reasons they cite is the poor return on investment, the potentially coercive nature of the payments, and concerns that payments could overall escalate vaccine fears. “In a climate characterized by widespread distrust of government and propensity to endorse conspiracy theories, those who are already Covid-19 vaccine hesitant might perceive that the government would not be willing to pay people to get vaccinated if the available vaccines were truly safe and effective. Incentive payments might also stoke new fears and, perversely, increase resistance to vaccination,” wrote Largent and Miller in January of this year.

As yet, there are few direct studies on the effects of financial incentives for vaccines. One such study was carried out by Phillipp Sprengholz, a graduate student in Media and Communication Science at the University of Erfurt. For his dissertation, Sprengholz is studying the variables that influence prosocial health prevention decisions. He investigated how the promise of a cash payment influenced about 1,300 German participants’ intent to be vaccinated against Covid-19 last December, before any vaccines were available. He found that a cash incentive did not have any effect on their intentions, and that was regardless of the amount of the payment. The results of his study are published in the Journal of Medical Ethics.

Sprengholz cautions that the study was carried out in Germany and may not apply to other countries and other cultural backgrounds. With that caveat, he says that the main driver of vaccination intention is confidence in the vaccine’s safety and efficacy. “If you believe that the vaccines were developed in a rush and that they are not safe, being paid one hundred or two hundred dollars will not change your mind,” says Sprengholz. “If you want to increase vaccination uptake significantly, you first have to improve confidence in the vaccines, and that’s not done with money, because then people may assume they are paid off for adverse effects.”

But even when vaccine incentives work, they may still be missing populations that are already lagging in vaccine uptake, argues Harald Schmidt, a Professor of Medical Ethics and Health Policy at the University of Pennsylvania. Schmidt’s work centers on improving opportunity and reducing disadvantage, especially for marginalized populations. In an essay published in Nature Medicine, Schmidt argued that disadvantaged communities should be prioritized for vaccination because the life circumstances of people in those communities makes them more at risk to catch and spread the infection, and at the same time they are more economically dependent on being healthy. 

Schmidt says that while the motivation for incentives is generally–though not always–pure, in many ways the best incentive is providing genuine access in convenient and trusted settings, “It is still the case that more vulnerable people need to get vaccinated much more urgently than better off people who can protect themselves more easily, and that has to be imperative. So we don’t just want to look at getting as many people vaccinated as possible, but getting those people vaccinated for whom it matters the most.”

Schmidt says that vaccine incentives are receiving disproportionate attention in comparison to real barriers that still stand in the way for people who want and need them. That requires more than a free donut or a cash payment, it requires partnerships with communities, according to Schmidt. “Incentives are a very narrow focus that may work for people who are procrastinators, but that’s not the group who we worry about, who’ve been left behind,” says Schmidt. He argues that dollars spent paying people to get vaccines could be more effectively used to set up vaccine clinics in disadvantaged communities with locations and hours that work for the people in those communities. This is an intervention with no downsides, unlike vaccine incentive payments. And community-based programs could also be replicated more easily around the world, he points out, in countries not wealthy enough to hand out checks to everyone who receives a vaccine.

In fact, a prioritization scheme based on economic disadvantage has been incorporated by the National Academy of Science, Engineering and Medicine in its vaccine allocation plan, and Schmidt says that those recommendations have been adopted widely, “We’ve definitely seen a very impressive commitment to equity that has been implemented in a range of ways.” 

For example, low-income communities are receiving 40% of California’s vaccine supply, with specific targets for hard-hit neighborhoods. That program include community outreach efforts like neighborhood canvassing, phone banking, at-home vaccinations and transportation services, plus a total of $85.7 million in funding to support community-based organizations. Under the state’s Vaccine Equity Metric, double the number of vaccine doses are being sent to ZIP codes with the lowest score on an index measuring factors related to health and life expectancy.