Prime Minister Boris Johnson has urged the public to continue following the rules despite successes with the vaccine rollout.

Posting a video on Twitter, Boris Johnson said on February 22 he would “set out the beginnings of our roadmap for a way forward for the whole country as the vaccine programme intensifies and, as more and more people acquire immunity, a steady programme for beginning to unlock.”

He added: “I want to stress that it is still early days and we have rates of infection in this country (that are) still very, very high and (have) more people – almost twice as many people – in our hospitals with Covid now than there were back at the peak in April.

“So, do remember how tough it still is, how high that rate of infection is and that we must, must work together to get it down – that’s the fundamental thing to get right. Stay at home, protect the NHS and save lives.”

It comes after the Government announced that more than half of all UK adults should receive a coronavirus vaccine by May, as the jabs rollout was buoyed by studies suggesting they are safe and effective against a new strain.

Downing Street confirmed that the vaccine programme planned to reach all those aged 50 and over, as well as adults aged 16-65 in an at-risk group, by May – having previously said it aimed to do so “by the spring”.

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Health Secretary Matt Hancock warned that “lots of things have got to go right” to hit the goal, including supply, but he said he was “sure” it was achievable. More than 10.9 million first doses have already been given.

According to the Government’s vaccines delivery plan, some 32 million people across the UK are estimated to fall into the first nine groups. There are 52.7 million people aged 18 and over in the UK.

The target was disclosed as the Cabinet Office announced that local elections in England and Wales would go ahead as planned on May 6 – though voters will have to wear face coverings and will be asked to take their own pen or pencil to mark their ballot.

It will be seen as indicative of lockdown restrictions easing in the spring, with reports that outdoor team and individual sports, as well as outdoor gatherings, could be possible within weeks of a planned return of schools from March 8.

The Prime Minister has faced sustained pressure from some Tory backbenchers to relax the measures as soon as possible.

However, scientists advising the Government have warned against opening society up too quickly.

Professor Graham Medley, chairman of the Scientific Pandemic Influenza Group on Modelling (Spi-M), said ministers should “make decisions dependent on the circumstances, rather than being driven by a calendar of wanting to do things”.

But Mark Harper, chairman of the Covid Recovery Group, made up of lockdown-sceptic Conservative MPs, said it will be “almost impossible to justify having any restrictions in place at all” by the time the top nine groups have been vaccinated.

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In a sign that the current measures are working, the reproduction number, or R value, of coronavirus transmission across the UK fell to between 0.7 and 1, according to the latest Government figures – down from between 0.7 and 1.1 last week.

And estimates from the Office for National Statistics (ONS) suggested about one in 65 people in private households in England had Covid-19 between January 24 and 30 – compared with one in 55 the previous week.

However, a further 1,014 people died within 28 days of testing positive for Covid-19 as of Friday and there were another 19,114 lab-confirmed cases of coronavirus in the UK.

Mr Johnson is due to publish a roadmap for lifting the restrictions in England later this month.