Around 10,000 people received jabs after slots were made available for those in the local area who had not yet been vaccinated.
People who are aged over 30 are being called up for a vaccination in England at the moment, but by 2.30pm event organisers said that anyone over 18 would be able to get an injection at the stadium as they did not want any of the vaccine to be wasted.
Huge queues formed around the famous venue as young people queued to get their first dose of the Pfizer jab.
Organisers said gates were closing at 6.45pm, adding that there had been an “amazing” response and thousands had been vaccinated.
Kira Lewis, 21, travelled from Hampstead Heath in north London with her partner, Nathan Burns, 24, to get her jab after seeing it was available on Twitter.
In a tweet, she described the queue a as "bigger than glastonbury".
"Just made it to the end of the queue! Bigger than the ones I used to be in to get into Glastonbury", she said.
"Almost everyone under 30!"
The King’s College graduate, who now works at Labour First, said she had been queuing since 5.15pm.
She said: “People here are generally high-spirited, and lots have come with friends. I’ve seen a few people I know from university pass me and join the queue.
“We came from the other side of London for it, as it’s worth the opportunity. Despite seeing the huge queue that is snaking around the stadium people are still keen to join, with some running to get to the back.”
She said the couple saw the tweet “and we thought we might as well”.
She added: “We want to help protect others and it’s maddening to see the Government say we won’t want it. I want it so I can feel safer visiting my family and at work when I’m around people who can’t get vaccinated for medical reasons.
“It felt like we either get it today or potentially wait months for the next opportunity.
“I hate needles. But it’ll have to be done sooner or later and getting the vaccine is definitely for the best. I had coronavirus at Christmas and it was horrible. It’s better to avoid it again or passing it on.”
Scotland international rugby union player Rory Hutchinson was also among those who got a vaccination.
The 25-year-old Northampton Saints player said that “for me it is the right thing to do and that is why I am here today”.
He said: “It was a really smooth process. I thought they were very professional. It was easy to find. I walked straight in and got my vaccine done. Then just had to wait a short while to make sure I was OK.
“I think we have been through a really tough time recently and hopefully we are on the mend now. I am just doing what I can to support that.”
Student and sports fan Flo Flake-Parsons said it was “quite exciting” to get her jab in a place “where there has been so many happy memories”.
The 24-year-old of Chiswick, west London, said there were no queues by the time she got her afternoon injection.
Saying it was “quite a relief” to the get the vaccination, she added: “It has been a really rubbish time for everyone and this is a good step back towards normality.”
Dr Genevieve Small, who is a Harrow GP and the clinical lead for the north west London vaccination programme, described the Twickenham event which had been organised in a short space of time as a service which had been “something quite powerful” for a range of people.
She said: “We have been able to provide this facility on the day for people who perhaps knew they were allowed to get the vaccine but had not come around to sorting it out, or who have just been more spontaneous, or who had previously questions about the programme and now feel ready to come forward for the vaccination.
“There is, of course, a want (or a need) to make sure we are protecting the areas that are seeing more cases of the new variant.
“We have been given the opportunity (to do this). We have been given the vaccine and we have gone for it.”
Over 100 vaccinators, which includes a mixture of GPs and nurses, were on duty to hand out the jabs.
Pippa Nightingale, chief nurse for North West London, said: “We made a local clinical decision to widen the vaccination offer today to ensure all the available vaccine could be put to use without waste.
“We got a huge response from the public, to the point where we had to close the gates to walk-ins at 6.45.
“We’re really sorry for anyone who was disappointed – for those eligible, please do book through the national book on system.”
Twickenham Stadium venue director Mark Lynch said: “We are proud to have supported the NHS for over a year during the pandemic, first with a test centre in Twickenham Stadium car park and now to set up this mass vaccination facility in record time.
“It’s taken less than a week to turn around and I’d like to thank all 600 stadium and NHS employees involved for their hard work to make this happen.
“Like rugby clubs across the country, we feel it’s important for us to do our bit to support our local communities.”
The event has been organised by the local NHS trust in partnership with Hounslow Council and supported by England’s Rugby Football Union (RFU).