The US state of Ohio will award cash prizes of $1m (£710,000) to five recipients of Covid-19 vaccines as part of a lottery launched to boost flagging up-take of jabs.
Ohio Governor Mike DeWine said only adult residents who had had a vaccine would be eligible for the draw.
The first of five weekly drawings will be announced on 26 May, Mr DeWine said.
He said the lottery would be paid for by coronavirus relief funds from the federal government.
A world leader in Covid-19 vaccinations, the US has given 58.7% of its adult population jabs against the disease.
A successful vaccination programme was crucial to curbing the pandemic in the US, which has recorded more than 32 million infections in total - the highest figure in the world.
President Joe Biden has set his administration the goal of vaccinating 70% of adults by 4 July - American Independence Day.