More than 1.6 million people will be invited to book their COVID-19 booster jab next week as the vaccination programme continues to be rolled out.
People across England, who are newly eligible, for the third dose will receive an invite to book their booster online.
Around 9.5 million invites, including texts, letters, and emails, have been sent out already and more are due to land on doorsteps next week.
According to NHS England, the latest figures show more than half of eligible people aged over 50, and more than two-thirds of people over 80, have already received their booster shot.
On Friday, official figures showed more than 7 million people vulnerable people across the UK have now been given a COVID-19 booster jab.
In six weeks, NHS staff and volunteers had delivered more than 6 million boosters in England alone, NHS England said.
Dr Nikki Kanani, deputy lead of the NHS vaccination programme, said: "It is encouraging to see that thanks to the efforts of NHS staff, millions of people have received their booster already and just over six weeks in, with over half of eligible over-50s already protected as we head into a winter like no other.
"I've recently had my booster at a local pharmacy and with more people becoming eligible every day I would encourage anyone who receives their text or letter invite to book an appointment and get their potentially life-saving top-up jab as soon as they can.
"The vaccine is simple, quick, and effective and will help us to give the country maximum protection from the virus."
More than 86 million vaccines have already been delivered and nine in 10 adults have had their first dose since the programme rolled out in December 2020.
People who are eligible for the third dose will be invited to book it at least six months on from their second dose.
They will receive a text invite from NHSvaccine, which will include a link to the NHS website to book an appointment at a vaccination site.
On Friday, Health Secretary Sajid Javid urged people to get their booster as soon as possible, to top up their protection over winter.
"Our life-saving booster vaccines are ensuring millions are protected over the winter - and it's fantastic that more than seven million people have now received their third jab," he said.
"This is a national mission and with over two million bookings in just one week, our booster programme is accelerating as more and more people become eligible. My thanks goes to the brilliant NHS staff and volunteers who are behind this huge effort to build our wall of defence.
"I urge everyone eligible to get their booster as soon as they can - and you can now book online or ring 119 once it's been six months and one week since your second dose."