I know a couple of people who don't plan to get vaccinated, who when they heard about the $1mn lottery idea scoffed: they recognize that the chance of them winning anything is negligible. One said they should have twenty $50k prizes instead and he'd go get his shots because that would be enough money to totally change his life and having twenty times as great a chance to win would be enough to make it worthwhile.
But you still have the same odds of winning any one drawing.
First of all, this isn't a Lottery (like the state lotteries) despite what they're calling it. It is basically a Raffle. In a Raffle, winners are chosen from among those who participate. Someone always wins a Raffle. Winning Lottery numbers are chosen irrespective of the tickets sold. That's why Lotteries roll-over all the time. Second, in a Raffle, chances are based on the tickets sold or in this case, shots given. If there are 1,000 shots given, your chances are 1 in 1,000. If there were twenty $50K prizes, your chances are 20 in 1,000.

