The coronavirus vaccine rollout is expanding to people aged 32 and 33 from today.
A further one million people will be able to book a COVID jab following the latest change, with a total of 50 million jabs expected to be administered by the end of Saturday.
It comes as the government revealed that two-thirds of England is now covered by sewage analysis for the virus.
Testing wastewater can show where coronavirus cases are present, and even which variants are in each area.
It has helped identify the need for surge testing in places such as Bristol and Luton.
While samples cannot be traced back to individuals, the equipment can be installed in focused areas like food manufacturing sites and prisons.
A laboratory dedicated to the programme was opened in Exeter in April, with 500 locations across England taking samples.
The Department of Health and Social Care hopes the technology will be able to help monitor flu outbreaks to predict which places will be badly affected.
The programme lead at the Joint Biosecurity Centre, Dr Andrew Engeli, said: "As infections fall and we head out of national restrictions, analysing wastewater to detect variants early on is important to help local authorities and NHS Test and Trace act quickly to stop variants from spreading in communities."
It comes as England’s R number range rose slightly to be between 0.9 and 1.1, up from between 0.8 and 1.1.
This means that for every 10 people who have the virus, between 9 and 11 more will be infected.
It follows the easing of lockdown restrictions and a rise in the Indian variant of concern – with more than 3,400 cases in the UK.
But Health Secretary Matt Hancock sought to reassure the public by emphasising the effectiveness of the UK’s vaccination efforts.
He said: "The vaccine has already saved thousands of lives and you are far less likely to get symptoms or be admitted to hospital if you get the jab."
More than 40% of adults have had at least one vaccine dose, with 2.6 million people booking a jab since under-40s were included last week.
Mr Hancock added: "This is truly a testament to the heroic work of our amazing NHS and care staff, volunteers and local authorities across the country who have helped deliver over 50 million jabs at lightning speed across England, keeping us on track to offer a vaccine to everyone by July."