In Canada, the U.K., and Israel, more than 65% of the population has received at least one dose; in the U.S. and EU, that figure is around 55%.

But as the vaccine drives complete their efforts with the most eager segments of the population, the vaccination curves have begun to flatten in several countries.

From France to Romania, from the U.S. to Serbia, the push to vaccinate the population has been hampered by a combination of distrust in the health care system, worry about long-term side effects, and the belief among younger people that their immune systems will be robust enough to easily beat COVID-19.

Faced with the prospect of not reaching herd immunity by the time winter arrives, many national and regional leaders have begun to offer incentives to entice their populations to take the jab. Sometimes with carrots, and sometimes with sticks.

First, the sticks…

On Monday, the French President Emmanuel Macron said vaccination would become compulsory for health care staff, and laid out tightening restrictions for where the unvaccinated would be able to go and what they could do. From July 21, vaccination will be required to enter leisure and culture facilities; by August, it will be required to enter everywhere from restaurants to hospitals, and to take long-distance trains.

“We must move towards the vaccination of all French people, because it is the only way to return to normal life,” Macron said.

The push comes as cases rise rapidly in France. About 55% of the population has received at least one dose of the vaccine, just above the EU average, but the pace of new vaccinations is slowing. Anyone over 12 in the country has the right to be vaccinated.

Macron’s stern moves to push vaccination appear to have had their desired effect.

At one point on Monday, the Doctolib medical booking website reported that 20,000 appointments were being booked every minute. The site later said that a total of 926,000 people had booked a first dose through the platform on Monday, “an absolute record.”

On Tuesday, the booking continued to pour in, with another 800,000 using the site to book a jab by 4 p.m. local time.

Macron isn’t the only leader on the continent to choose the blunt instrument of making vaccination mandatory for large swaths of the population or most leisure activities.

The Czech government has said that vaccines will be mandatory for children returning to school in September; in Moscow, the Russian government has warned that at least one shot will be mandatory for those in service positions, from transport to restaurants, by mid-month; and in Greece, Prime Minister Kyriakos Mitsotakis this week made the vaccine mandatory for health care workers.

…and the carrots

The hard-nosed dictum of “Get vaccinated or lose your job” has been accompanied by a host of more benign incentives used by Russian officials and companies to push up low vaccination rates, including raffles for free cars, snowmobiles, and all-expenses-paid trips.

In Romania, where distrust of government authorities has reportedly stalled vaccine uptake, local officials have offered free meatballs in return for jabs, and staged vaccinations at the castle believed to have inspired Dracula. 

In Bulgaria, the government takes the approach of letting residents choose which brand of vaccine they would like to receive.

In Greece, the incentive on offer is a 150 euro ($177) digital debit card called a “freedom pass,” which will be given to every person between the ages of 18 and 25 who gets vaccinated. The app-based cash card, which will be valid from this week through the end of the year, will be usable for travel and cultural activities.

“It’s a debt to the youth, a gift out of gratitude,” Prime Minister Kyriakos Mitsotakis said when unveiling the scheme a couple of weeks ago, as part of a drive to achieve an 80% vaccination rate by the fall.

However, Greece’s incentive is positively coy when compared with that rolled out in Serbia during the month of May: a straight cash payment of 3,000 dinars ($30).

The Serbian measure came in the context of a vaccination drive that was starting to hit the buffer of hesitancy. It was instantly controversial, with some ethicists saying the offer could be seen as coercive when it comes to poorer people who desperately needed the money, and others saying this could not be possible while people were still free to refuse vaccination.

As it turned out, Serbia’s case rate continued a steady decline after the cash offer was deployed; it is difficult to say how much of that was a result of the incentive. The Balkan country now has a seven-day incidence rate of just nine per 100,000 people. (Greece’s is 129.)

Ireland, like the U.K., has very low vaccine hesitancy rates, but like many other countries, Ireland is struggling to vaccinate its youth. Worry surrounding its long-term side effects has been cited by young people who believe that if they do become ill with COVID-19, their immune systems will be strong enough to cope.

There has not been any incentive scheme as of yet, but this week, Ireland’s youngest parliamentary delegate suggested the government should dish out €150 cash bonuses to encourage young people to get the jab.

However Ireland’s Economic and Social Research Institute (ESRI) quickly came out against any incentive scheme, noting vaccine hesitancy remains a fringe stance across all ages in Ireland and the cost of any incentive scheme would likely outweigh the benefits.

Such inventive schemes could also have negative effects on current or future vaccination drives.

Jan-Ole Reichardt, an ethicist at the University of Münster, says incentivizing vaccination could arguably “transform an altruistic behavior into a merely instrumental one,” leading to a “worse off society than before.” He warns there could be negative consequences down the line, when new health threats emerge.

“Adding financial incentives now might lead to less altruistic communities in the future. So it’s something we should think about a bit longer,” Reichardt says.

And as Serbian epidemiologist Zoran Radovanovic put it to The Lancet at the time of Serbia’s vaccine incentive scheme: “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.’”