More than five weeks into the third national the national R rate has fallen below one for the first time since July, but when will lockdown end?

The Prime Minister is set to give an update on when lockdown will end later this month.

Speaking today, Boris Johnson has said he is “optimistic” he will be able to begin announcing the easing of restrictions when he sets out his “roadmap” out of lockdown in England on February 22.

Speaking during a visit to the Fujifilm Diosynth Biotechnologies plant in Billingham, Teesside, where the new Novavax vaccine will be manufactured, the Prime Minister said: “I’m optimistic, I won’t hide it from you. I’m optimistic, but we have to be cautious.”

He said his first priority remained opening schools in England on March 8 to be followed by other sectors.

“Our children’s education is our number one priority, but then working forward, getting non-essential retail open as well and then, in due course as and when we can prudently, cautiously, of course we want to be opening hospitality as well,” he said.

“I will be trying to set out as much as I possibly can in as much detail as I can, always understanding that we have to be wary of the pattern of disease. We don’t want to be forced into any kind of retreat or reverse ferret.”

The legislation for the latest lockdown, which began on January 6, lasts until March 31 but the speed at which measures are eased is reliant on Britain's vaccination efforts.

Last month, Boris Johnson signalled the Government was targetting to reopen schools by March 8 and recent reports have suggested non-essential shops and pubs may reopen in April.

The Government is said to be set to hit its UK-wide target of offering a Covid-19 vaccine to people most at risk by Monday.

NHS England said the top four priority groups in England – people aged 70 and over, care home residents and staff, health and care workers and clinically extremely vulnerable patients – “have now been offered the opportunity to be vaccinated”.

It comes as Government data up to February 11 shows that 14,012,224 people in the UK have now received a first dose of the vaccine.

It comes as the reproduction number, or R value, for coronavirus is now estimated to be between 0.7 and 0.9 across the UK.

This is the first time since July that R has been this low, and shows that lockdown restrictions are having an impact and the epidemic is shrinking.

But while scientists advising the Government believe cases of Covid-19 are dropping at a decent pace across England, they have warned that infection levels remain high.

Prime Minister Boris Johnson is facing calls from Tory sceptics to ease the lockdown once the pressure on the NHS eases and deaths drop.

But scientists argue that case numbers are still too high for a significant loosening of restrictions.

They believe that only by driving case numbers to much lower levels can NHS Test and Trace and surge testing work properly.

With low case numbers, clusters of cases can be identified more easily and new mutations to the virus can be picked up, one Government scientific adviser said.

Mr Johnson said: "

Boris Johnson said today while coronavirus infection rates are falling, overall numbers remain very high.

“We have made huge progress with the rollout of the vaccines. That is great,” he said during a visit to a vaccine manufacturing facility in Teesside.

“But we have still got infections running very high throughout the country – levels which last year we would have thought were really very high indeed (and) still sadly a great many deaths in our hospitals.

“Although the number is beginning to come down, and perhaps starting to come down quite fast, we need to look at the data very, very hard.”

He added: “Something also that will be very important is the efficacy of the vaccines – are they working in the way that we hope that they are? – and making sure they are really helping, along with the lockdown, to drive down the incidence. That is the key thing.”