A circus, festivals and sporting events are among the "pop-up" vaccine clinics opening to encourage more people to get vaccinated against Covid-19.
NHS England said more than 31.5 million people were double-jabbed and it wanted "as many vaccinated as possible".
Health Secretary Sajid Javid said it was "saving thousands of lives".
Spectators and passers-by at the Circus Extreme in Halifax were being offered a jab outside a tent of jugglers, acrobats and stunt performers.
John Haze, circus director, said: "It may not be the normal thing you expect to see when you enter the Circus Extreme Big Top, but we are really proud to be supporting the NHS Covid vaccination programme.
"We had no hesitation in letting the NHS host a walk-in clinic in the tent so that more people can get their jab at a convenient time, and we hope lots people will take up this offer."
Festivals in London hosting walk-in clinics included a bus parked at the Summer of Love Festival in Holland Park and a four-day vaccine event with live music in Poplar.
Burnley FC in Lancashire and the Goodwood Racecourse in West Sussex, which is hosting the Stewards' Cup, were among other venues being used in the vaccine push.
From 7 August, nightclubs will also start to offer vaccines including the Nightingale in Birmingham.
Jeremy Joseph, who owns the G-A-Y nightclub chain, said his Heaven club in London would also be turned into a pop-up vaccination centre.
'Biggest vaccination programme'
GP Dr Nikki Kanani, deputy lead for NHS England's vaccination programme, said more than 2,000 sites had already taken part, including Thorpe Park in Surrey.
"Thanks to the incredible hard work of NHS staff and volunteers across England in what has been the biggest and fastest vaccination programme in health service history, nearly nine in 10 adults have received at least their first dose of the Covid vaccine, giving them crucial protection against coronavirus."
She said more than 70 million doses had been delivered with "87% of adults having had at least one dose, and seven in 10 now fully-vaccinated".
But the latest figures show nearly a third of young adults aged 18 to 29 in the country have still not had one jab.