These are the different schemes around the world promoting people to get vaccinated

Authorities and companies are offering a dizzying array of incentives to boost COVID vaccination rates and turn a page on the pandemic.

Get a COVID-19 jab in Moscow and you could leave with a lot more than a sore arm - the city is giving away five cars a week in a prize draw for residents who get vaccinated.

Londoners who get inoculated had the chance to win tickets to the final of The Euro 2020 soccer Championship and residents of California are in with a chance of scooping a $1.5 million lottery jackpot. Romanians who get a vaccine dose, meanwhile, are being rewarded with a barbequed sausage sandwich.

From dollars to cows, donuts and even drugs, a dizzying array of incentives are being offered by authorities and companies around the world in a bid to win around the vaccine hesitant as they seek to turn a page on the pandemic.

But as countries strive to reach 'herd immunity' - where enough people are protected against a disease that it becomes difficult for infections to spread - others are opting to slap fines and other penalties on anyone who refuses the jab.

As mass vaccination drives progress around the world, which approach is proving more effective?

Researchers developed highly effective vaccines against COVID-19 in record time, but many people are reluctant to take them, often because they worry about the safety of the vaccines or fear rare but serious side-effects.

That has prompted officials to look for ways to convince them otherwise.

In some cases that might involve allaying health fears and tackling "fake news" with information campaigns, or making sure vaccines are easy to access. But officials are also using perks - and occasionally punishments - to persuade people to go ahead.

Some U.S. states are holding lotteries for vaccinated residents with large cash prizes on offer, with Cambodia kicking off a similar incentive.

California's $116.5-million plan is designed to encourage more people to get the jab ahead of June 15, when many coronavirus restrictions are set to be lifted. Thirty people have already scooped $50,000 prizes, with another 10 Californians in line for a $1.5m payout. The state is also giving out 2 million $50 gift cards.

In Moscow, which is battling a surge in coronavirus cases, anyone who receives the first of a two-dose vaccine up until July 11 was entered into a draw with five cars worth 1 million roubles ($13,900) being given away every week.

In a Philippine town, the mayor is planning a cow raffle as an incentive, while another community has been raffling off huge sacks of rice, after finding it hard to persuade people to get their shots. Mexican vaccination centres are instead laying on entertainment in the hope of making it fun to get a jab.

Businesses are also getting in on the act, from free beer in Israel to complimentary dessert in Malaysia. In Hong Kong, a property developer is raffling off a $1.4 million apartment for people who have been vaccinated.

And Washington State has allowed retailers to offer a free marijuana joint when they get a shot in ‘joints for jabs’ promotions.

Many companies say they want to support the vaccine drive out of concern for their home communities. Offering deals and freebies can also be a financial boost for firms that might hope customers linger and buy more.

Some companies are hoping to persuade employees to get their jabs by offering cash bonuses.

Popular psychology suggests rewards are more effective than punishment, but research on vaccine hesitancy indicates that both can be effective in certain contexts.

Mandates and sanctions for non-vaccination were effective in increasing uptake, according to a review of studies carried out by the World Health Organization in 2014, with cash incentive schemes seen as likely to be less successful.

More recent research found incentives helped seal the deal.

About a third of unvaccinated Americans said they would be more likely to get the coronavirus shot in return for $100, found a survey by the University of California, Los Angeles, though some 20% said a cash reward would put them off.

And what are the medical ethics of these schemes?

Incentives are an ethical way forward while deterrents and punishments should be wielded with great care, said Nancy Kass, deputy director for public health at the John Hopkins University's Berman Institute of Bioethics in the United States.

"It's always better ethically to at least start by providing information, encouraging people, making it easy for people and doing all of those kinds of things before moving to a mandate," she told the Thomson Reuters Foundation by phone.

Relatively few people are "deeply philosophically opposed" to getting a shot, which means inducements and nudges might be enough to reach the numbers needed, she said.

And there is a significant moral difference between restrictions that push people to weigh up their options as compared to heavy fines that leave them with little real choice, Kass said.

"My fear is people jumping to (compulsory orders) as a first strategy rather than a last-mile strategy," she said.