SACRAMENTO — California will offer US$116.5 million (S$150 million) in cash and gift cards to residents who get Covid-19 vaccinations before June 15, the latest — and most lucrative — incentive by US states desperate to persuade laggards and vaccine-sceptics to get the injection.

The move by Democratic Governor Gavin Newsom is part of an effort to boost vaccinations as the state prepares to fully reopen its economy on June 15. Ten Californians who become inoculated before that date stand to win lottery-style prizes of US$1.5 million apiece, while another 30 people will each win US$50,000.

Beginning Thursday, the first two million Californians to become vaccinated will each win US$50 gift cards for cash or groceries, the state said.

"Some Californians weren't ready to get their Covid-19 vaccine on day one, and that's OK," said Dr Tomas Aragon, director of the California Department of Public Health. "This program is designed to encourage those who need extra support to get vaccinated and help keep California safe."

With a few exceptions, all Californians who became vaccinated since vaccinations were first available in the state will be entered into drawings for the larger prizes, Newsom said at a news conference in Los Angeles on Thursday.

The incentives are being offered as Newsom is fighting off a recall campaign that has become a cause celebre among Republicans nationwide. It is one of many ways that Newsom plans to spend an unprecedented state budget surplus.

"Getting every eligible Californian vaccinated is how we bring our state roaring back from this pandemic," Newsom said.

Across the United States, states and private organizations have offered incentives to persuade people to become inoculated against Covid-19, which has killed nearly 3.7 people worldwide.

The incentives range from free baseball tickets and beer, to college scholarships and cash.

On Wednesday, Ohio awarded US$1 million to Ms Abbigail Bugenske, a Silverton woman who entered the state's Vax-a-Million drawing. Joseph Costello, a high school student from Inglewood, won a full-ride scholarship, including tuition, books and room and board at an Ohio public university or college. REUTERS