Gov. Kate Brown announced Friday lottery prizes ranging from $10,000 to $1 million for Oregonians vaccinated against COVID-19 — a strategy meant to address the dramatically decreasing numbers of residents inoculated each day.

All residents 18 and older who’ve received at least one shot of COVID-19 vaccine by June 27 will be entered into the “Take Your Shot Oregon” lottery, which will be held on June 28.

One lucky vaccinated Oregonian will receive a $1 million jackpot and 36 others — one from each Oregon county — will win $10,000 prizes. That means residents in the least populated counties — tiny Wheeler County has just 1,440 residents — will have a far better chance of winning a $10,000 prize than residents in the most populous counties. Multnomah County is the largest with about 830,000 residents.

Oregon Lottery rules don’t allow anyone under 18 to participate in the cash drawings, but a special drawing will be held for vaccinated children ages 12 to 17. Five winners will each receive $100,000 contributions to Oregon College Savings Plan accounts in their names — money that can be used for college or trade schools.

Winners will be announced about a week later, most likely by July 4.

As of Friday, 52% of Oregonians have been partially vaccinated and 40% have been been fully. The average daily number of shots administered peaked at about 43,000 on April 11, but since have plunged to below 30,000. Nationwide, the rate of inoculations has fallen even faster. Experts say herd immunity — the point that the coronavirus can no longer spread because there are so few hosts — is estimated at between 70% to 85% immune either through vaccinations or natural immunity from past bouts with the disease. Given plummeting numbers, many epidemiologists and others are skeptical the United States will ever reach herd immunity.

“We will need to pull on every lever we have,” Brown said, during a live-streamed news conference Friday. “So if you’ve been waiting to get a vaccine or you just haven’t gotten around to it yet, we’re going to give you an extra incentive. How about a chance to win a million dollars?”

Brown added: “It can save your life and just maybe make you a millionaire.”

Although Brown said Oregon had been exploring the idea for weeks, after Ohio Gov. Mike DeWine was the first in the nation to offer a COVID-19 vaccination lottery last week, Brown said Oregon officials contacted Ohio officials for details. DeWine said hold a $1 million lottery each week for five weeks — randomly selecting names from voter registration rolls and giving away the cash only to winners who are inoculated. A similar Ohio drawing will offer four years of free state tuition, room, board and books to the college-bound.

Within a day of Ohio’s announcement, vaccinations began to jump and have kept on surging.

In Ohio, it’s possible that some of the names drawn will be of people who are not vaccinated. If that’s the case, Ohio will apparently draw new names, until winners who actually are vaccinated have been selected. That — avoiding the disappointment that would come with even the very slim chance of being selected and declared ineligible — could conceivably serve as extra motivation to get vaccinated.

In Oregon, the process will be different. Only vaccinated people will be entered into the lottery, which will use names from the Oregon Health Authority’s database of people inoculated against COVID-19. But officials want to be very careful about protecting privacy, so the health authority will only give lottery officials individual identification numbers assigned to each vaccinated resident. The lottery will draw from those numbers, then notify the health authority of the winners.

Oregon winners will have the option of declining the prize money. But the names of those who accept the money will be made public.

The “Take Your Shot Oregon” program appears to generating widespread excitement, but some critics have likened it to a bribe to get vaccinated. But a key presenter at Brown’s new conference Friday disagreed.

“This is not meant to be a bribe, it’s an incentive,” said Ashby Monk, who is executive director of the Stanford Global Projects Center and has studied ways to motivate people to make decisions that benefit themselves and society. He said campaigns to encourage certain behaviors are far more successful if they’re based on incentives rather than fear, such as in this case reiterating the consequences of not getting shots.

“I think people can opt out, they don’t have to play the lottery if they don’t find the incentive appealing,” Monk said. “I don’t think many people will.”

All Oregonians 12 and older will automatically be entered into the cash or scholarship lotteries, as long as they’ve been vaccinated with at least one dose of COVID-19 vaccine. The state will not allow anyone stating that they can’t be vaccinated for religious or health reasons to take part in the drawings.

Oregonians vaccinated in other states will be entered into the drawings because they are registered in the state’s database of vaccinated residents, officials said. But residents vaccinated at federal sites such as those run by Veterans Affairs or tribes aren’t currently slated to be entered into the lotteries because of data transfer problems, but state officials said they are hoping to change that in the next week.

State data shows Oregon, with about 4.2 million residents, has administered at least one dose to about 2.1 million people. Although some of those people aren’t Oregon residents, by far most are and the figure gives a good idea of the number of residents who are eligible for the vaccination drawings so far.

To learn more about many of the specifics of the vaccination lottery, visit this Frequently Asked Questions sheet created by the state.

This is a developing story. Check back later on OregonLive.com for more details.

— Aimee Green; agreen@oregonian.com; @o_aimee

This content was originally published here.