Three-quarters of adults in the UK have received a first dose of a Covid-19 vaccine, health agency figures estimate.
The milestone comes the day after zero deaths within 28 days of testing positive for Covid-19 were reported, for the first time since July 30 last year.
Triumphant Matt Hancock said he was often told we wouldn't have a vaccine until well into 2021 but he said he was "optimistic" and always believed we would be ready to deploy a vaccine as soon as it was ready.
"Vaccine confidence and uptake are among the highest in the world and I'm very proud of that," the Health Secretary said.
He said the clinical prioritisation of jabs has been critical and helped demonstrate that the system is fair, also praising the NHS and the "scientific strength" of the UK.
Mr Hancock said the devolved nations have worked together collectively to "pull off" the vaccination programme and save lives.
Speaking at the Jenner Institute in Oxford ahead of the G7 health ministers' meeting, Matt Hancock said: "I specifically remember a then meek and timid professor turning to me when I asked how fast this could possibly be done.
"He said that if everything went right then the very best we could hope for would be 12 to 18 months.
"Who would have thought that just 11 months later we'd be the first country in the world with a clinically authorised vaccine and that professor Jonathan Van Tam would be turning down Strictly."
He added: "The clinically advised prioritisation for getting vaccines in arms has been critical, I believe, in securing trust in the programme overall because it's helped demonstrate that the system is fair.
"So, we acted early to reassure people that in the finest tradition of the values of the NHS, vaccines will be given according to need, not ability to pay - whether you're the Prime Minister, or Premier League footballer or the future king of England. You have to wait your turn, just like everyone else."
Half a billion doses of the Oxford AstraZeneca vaccine have also been released for supply globally, the Health Secretary said.
Mr Hancock said the vaccination programme has been emotional and spoke of seeing smiles on faces when he has visited vaccination sites.
He said it has given "hope for the future" that we can put the pandemic behind us, thanking everyone who has made it happen.
Currently people aged 30 and over can book to get their jabs with the NHS.
But the June 21 end of lockdown is hanging in the balance after Boris Johnson warned it is still too early to say if he can lift restrictions.
Chris Hopson, chief executive of NHS Providers, described the latest milestones in the vaccination rollout as an "incredible achievement", with three-quarters of adults in the UK having received a first dose and 50% of adults in England having been given both jabs.
He added: "We know vaccines are breaking the chain between infection rates, hospital admissions and death. But we also know two doses are better than one, particularly in our fight against the Delta (Indian) variant.
"So while there's a lot to celebrate, we've still got a way to go before people have had both jabs. We also know it takes three weeks for doses to be fully effective.
"We urge everyone to get their jabs when they're offered them."
The Prime Minister today said "at the moment" he can see nothing that shows step four must be delayed - but warned the data is too "ambiguous".
Mr Johnson said: “I can see nothing in the data at the moment that means we can’t go ahead with step four, all the reopening on June 21, but we’ve got to be so cautious.
“Because there’s no question the ONS data of infection rates is showing an increase.
"We always knew that was going to happen…. What we need to work is out is to what extent the vaccination programme has protected enough of us, particularly the elderly and vulnerable, against a new surge.
“And there I’m afraid the data is just still ambiguous.
“And so every day we’re having long sessions, we’re interrogating all the data, we’re looking at all the various models, and the best the scientists can say at the moment in their guidance to us is we just need to give it a little bit longer.
“I’m sorry that’s frustrating for people, I know people want a clear answer about the way ahead for June 21, but at the moment we’ve just got to wait a little bit longer.”
The UK was one of the first countries in the world to start a vaccine rollout in December last year.
By April, all over-50s and those clinically vulnerable had been offered a first dose, with Margaret Keenan, 90, from Coventry, the first person in the country to get the Pfizer Covid jab.
Boris Johnson also today said the Government will have "no hesitation" in moving countries around the red, amber and green lists of travel restrictions.
Asked whether there may be more countries added to the green list soon, where there are no requirements to quarantine on returning to the UK, the Prime Minister said: "You've got to wait and see what the Joint Biosecurity Centre say and what the recommendations are about travel.
"We're going to try ... to allow people to travel, as I know that many people want to, but we've got to be cautious and we've got to continue to put countries on the red list, on the amber list, when that is necessary.
"I want you to know we will have no hesitation in moving countries from the green list to the amber list to the red list, if we have to do so.
"The priority is to continue the vaccine rollout, to protect the people of this country."
