The decision to pay €25 per person is raising ethical questions and concerns that the scheme could backfire. Ed Holt reports.In what local experts say is a world first, Serbia has begun offering cash payments to people to receive COVID-19 vaccinations. President Alexander Vučić said on May 5, that anyone who gets vaccinated by the end of the month would be paid 3000 Dinars (around €25), around 5% of the average monthly salary.The move comes as what had been an impressive vaccination programme begins to slow. Serbia is using the Oxford–AstraZeneca, Pfizer–BioNTech, Sinopharm, and Sputnik V vaccines. As of May 5, 3·6 million people among Serbia's 6·9 million population had received a first dose, and 1·6 million had been given both doses, according to government data. However, uptake has slowed in recent weeks amid apparent vaccine hesitancy.Vučić said the measure was to “reward people who showed responsibility”, but it has already been questioned by some disease experts in Serbia. Zoran Radovanovic, an epidemiologist at the University of Belgrade, told The Lancet: “There will certainly be poorer individuals for whom this financial incentive will overcome their reticence to vaccination.“[But] the offer of payment completely changes the perception of the purpose of vaccination. It would be natural for many people to think now: ‘If I am given money to take this vaccine, the vaccine is not good. There is a risk to it and a price has been put on that risk.’”Although Serbia's approach appears to be the first direct cash payment in return for vaccination, financial incentives have been offered elsewhere. In West Virginia, USA, $100 bonds are being given to people aged 16–35 years who get a COVID-19 vaccination.Ethicists are debating whether such schemes are right, or even effective. While financial incentives for vaccination against hepatitis B virus or HPV have been studied before, the novelty of COVID-19 makes the effects difficult to gauge. Nancy S Jecker, professor of bioethics and humanities at the University of Washington School of Medicine, told The Lancet: “It's an empirical question whether payment will increase rates of vaccination. Maybe vaccination rates will rise without payment. Or perhaps vaccination rates will decline with payment. Or perhaps other methods would work as well, or better. The honest answer is we don't know what the effects of payment would be.”Critics cite concerns over the potential effect on poorer and disadvantaged members of society. “A central concern, ethically, is that cash incentives yield unequal effects on different segments of society. In particular, they create undue influence on the most disadvantaged—those who lost their jobs or were furloughed, who struggle to pay rent and worry about eviction. Cash for vaccines may not feel coercive to the well heeled, but that is not a very compelling argument”, said Jecker.Keith Neal (University of Nottingham) argues that the money could be spent on other means of encouraging uptake instead. He told The Lancet: “Any money that can be spent on getting people to take the vaccine should be spent on providing better ways of delivering it to people who need it—for instance, running mobile vaccination sites.”Opponents of the incentives also warn that the payments could actually deepen vaccine hesitancy. Emily Largent, assistant professor of medical ethics and health policy at the University of Pennsylvania, said “there is good evidence from behavioural economics that offering money to someone to do something can make it seem like that thing is riskier or more burdensome. We have good evidence that COVID vaccines are safe and effective, and don't want to inadvertently create concerns by offering money.”Julian Savulescu, director of the Oxford Uehiro Centre for Practical Ethics and an advocate of financial incentives for vaccination, told The Lancet that the payments should be looked at as “payment for vaccination as a job”.“I call this the ‘payment for risk model’. It involves doing a formal economic calculation of how much should be paid for the overall risks involved, similar to how we calculate ‘danger money’ for risky jobs like construction or deep-sea diving.”He added: “Some people worry that payments may be coercive. That is a mistake—as long as people are free to refuse them, they can't be coercive. Coercion exists when a person's options are restricted, not expanded. The risk is exploitation, not coercion.”Serbia's scheme has only been running for a few days, but whatever effect it might have on vaccine uptake, Radovanovic said offering the payments has exposed a “failure” of Serbia's health policy, and blamed a paradoxical government approach to COVID-19 vaccinations for the slow-down in vaccination rates. “Offering money for vaccination is a defeat for health education policy. Serbia's populist government hosted both vaccination and anti-vaccination [opinions] in its media, leaving people confused.”