It's a good idea. At the end of the day these aren't normal times and low vaccine take up impacts the health and wealth of society. Needs must.
Other countries have been offering incentives for ages. Israel was offering free beer or a meal, America too - and some US states are also giving lottery tickets.
People can say unfair, but far better for individual and societal health and wealth to offer vaccine incentives than to do as Rishi Sunak did. Losing the taxpayer billions in lost stamp duty tax in order to worsen the homelessness public health emergency and further inflate the house price bubble.
I bet young people would prefer a vaccine lottery ticket over Sunak pushing house prices further out of reach for FTB.