People aged 25 to 29 in England will be able to book their Covid vaccination appointments from Tuesday, Matt Hancock has announced.
Speaking in the Commons on Monday, the health secretary said the pace of the vaccine rollout had been “extraordinary”.
It comes as Downing Street said the data emerging over the coming week will be “crucial” in deciding whether all legal coronavirus restrictions can end as hoped on June 21.
The prime minister’s official spokesman said a lot would depend on whether the vaccination programme had “sufficiently severed” the link between an increase in cases and hospitalisations and deaths.
“There is nothing in the data currently to suggest step 4 can’t go ahead at the earliest date,” the spokesperson said. “But we do need to look very closely at the data over this coming week.”
Hancock has said ministers are “absolutely open” to delaying unlocking if it was needed.
The vaccine push comes amid growing concern that the Indian variant is fuelling a surge in cases across Britain.
Of the 12,431 Indian variant cases so far confirmed in the UK, 10,797 are in England, 1,511 in Scotland, 97 in Wales and 26 in Northern Ireland.
NHS England chief executive Sir Simon Stevens said: “Today is a watershed moment as the world-beating NHS vaccination programme enters the home straight of our race to offer everyone their first dose.
“The NHS vaccination programme is a real team effort and it is a testament to NHS teams across the country that we are able to open up to people in their 20s just six months on from delivering that world-first jab to Maggie Keenan.
“The tireless efforts of NHS staff to protect the people they care for and their communities has quite simply saved lives, and when you get the text, you’re next.
“Getting the lifesaving Covid-19 jab is the most important thing you can do, with NHS staff vaccinating at over 1,600 sites, including vaccine buses, places of worship, sport stadiums and other convenient locations. So when you get that text, book your appointment and join the millions who are already protected.”
Alongside opening up appointments to younger age groups, the health service is pressing ahead with offering second doses to people at pace.
The so-called race between variants and vaccines has led to a sped-up timetable for offering second jabs.
Instead of waiting 12 weeks for their second dose, people are now being invited back for their second dose after eight weeks.