Text messages will be sent to 650,000 people this week encouraging them to bring forward their second Covid-19 jabs.
The drive to speed up the country’s vaccine rollout comes shortly ahead of the lifting of coronavirus restrictions on Monday.
So far, more than 29 million people in England have received both doses, while a further 9 million people have had their first shot.
Earlier this year, the recommended waiting time between injections was 12 weeks, but this has been lowered to eight weeks in all age groups.
Since mid-May, more than 2.5 million people have rescheduled their second vaccine appointments for an earlier date.
Most of these rebookings were made by people over the age of 40, as the government only advised younger adults to have their jabs eight weeks apart on 5 July.
This week’s text invitations will include a link to the relevant NHS website, allowing people to book in their final vaccinations sooner than expected.
Those who cannot go online can rearrange their bookings by calling the health service on 119.
Sir Keith Willett, the NHS lead for vaccinations, praised health workers for their hard work in fully vaccinating two-thirds of England’s adult population.
He urged others to “protect themselves and their local communities” by taking up the NHS’ offer as soon as possible.
“As we approach 19 July, there has never been a more important time to get jabbed and it has never been easier – from pop-up sites in the community to walk-in centres, NHS staff are going to great lengths to ensure vaccines are as convenient as possible,” he added.
Sajid Javid, the health secretary, also encouraged people to have their second jabs eight weeks after their first, saying that it would allow the population to “enjoy the freedoms we’ve missed”.
“Two doses of a Covid-19 vaccine provide up to 96 per cent protection against serious illness and hospitalisation from the virus, so it is absolutely crucial everybody gets both doses,” he said.
Although some vaccine centres have been giving second injections to people just three weeks after they received their first, the Joint Committee on Vaccination and Immunisation (JCVI) has said an eight week gap is better, as it offers more protection against the virus.
Professor Anthony Harnden, deputy chair of the JCVI, told Times Radio on Wednesday that the data shows that “there is a lower vaccine efficacy against symptomatic disease with shorter intervals compared to longer intervals”.
