Washington state’s new “joints for jabs” programme linked to Covid-19 vaccinations is off to a rough start.

Officials announced on Monday the state’s nearly 500 licensed marijuana retailers could begin hosting vaccine clinics and offering a single, free pre-rolled marijuana cigarette to any 21-plus adult who received a shot there.

It is one of many vaccine incentives being offered in Washington, including free pints of beer, sports tickets and prizemoney to lure those who have been hesitant or lazy.

Washington and Colorado in 2012 were the first states to legalise the adult use of marijuana, with regulated sales beginning in 2014. The industry brought Washington close to 474 million dollars (£336 million) in taxes in the last fiscal year.

But few things are simple in an industry that is illegal under federal law, and the hurdles to offering the free joints are substantial enough that few of the state’s legal pot shops are saying they will participate, even if they would like to do so.

Retailers told the state Liquor and Cannabis Board during a meeting on Wednesday that many did not have the space to host a vaccine clinic.

Some health care providers are uneasy about setting up a clinic on the site of a marijuana business because they do not want to jeopardise federal funding by being involved in the distribution of an illegal drug.

And the programme is set to expire on July 12 — too soon for the shops to offer a second shot to customers who might show up for a first shot in mid- to late June.

The retailers also ruefully noted that the Liquor and Cannabis Board allowed breweries, wineries and bars to offer a free drink to customers who merely showed proof of vaccination, with no onsite clinic required.

“We’re hearing from retailers that they want to be a part of this,” said Aaron Pickus, a spokesman for the Washington CannaBusiness Association, an industry group. “Why can’t we do this like the wineries and breweries did it?”

Board chair David Postman told them it was a member of the business group who late last month suggested the programme, which he and Governor Jay Inslee’s office had considered a great idea.