Military personnel deployed to help with the booster programme have spoken of the "fantastic" NHS staff they work alongside and their pride in taking part.
About 1,300 members of the Armed Forces have been brought in to help deliver what the Prime Minister branded a "national mission" to combat a surge in cases of the Omicron variant of the virus.
Private Tia Walker, an Army Combat Medical Technician, was deployed to the St John's vaccination centre in Preston with just 24 hours' notice.
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The 23-year-old said: "The NHS staff we've been working with have responded really well to us.
"We're here to boost their numbers and while they're feeling that the pressure is still on, there are more of us to help and switch out with them.
"Us being here means they can have that five-minute break and get a cup of tea.
"So I feel like I'm helping them and boosting their morale by being here alongside them and getting them through it," she added.
Flight Lieutenant Danielle Harper-Dixon, 35, was deployed to the Castle Mall shopping centre in Norwich.
Her team were told about their task on a Friday, trained over the weekend, and by Monday they were in Norwich dosing about 1,700 people a day.
She said: "The NHS workers we're with are absolutely fantastic. We've met some really resilient, amazing individuals who are going through it day in, day out.
"It’s not an easy job, it's stressful and tiring. Working amongst them makes you realise how difficult that job actually is.
"The response we've received as members of the Armed Forces has been amazing, too. Our NHS colleagues were so relieved when we arrived, we got a round of applause because we're here to help."
She added: "And the reception that we've had from the public has been brilliant. Everybody's saying 'thank you for your service', it's lovely to hear and really humbling."
Like a lot of her team, she has had to cancel Christmas plans to be part of the booster effort. But, she says, it's part of the job.
She said: "We're all here for the main effort. And everybody's, you know, putting their personal lives aside to make it happen. I feel really proud and privileged to be able to contribute."
Flight Lieutenant Matthew Lomax was deployed to support the COVID vaccine effort as a military planner in Nottinghamshire.
Within 24 hours he had set up a new pop-up vaccine centre at Newark Showground and is now involved in the day-to-day running of the site.
He says working with the local community had been "amazingly positive".
"The uptake has been fantastic. People seem to be extremely happy to get the booster closer to home without having to book," he said.
But the work has also taken on a personal slant because of his family connections to the NHS.
He added: "The NHS is important to me as my mum has been an NHS nurse for over 30 years, so to work with them and its staff is a great experience for me.
"The way they have pivoted from one issue to another and worked a huge amount of hours throughout COVID has been incredible to see. It's a privilege to work with the staff here and help in any way I can."