Government scientists believe the reproduction number – the R – for coronavirus has fallen to below 1 across the UK, suggesting a retreating epidemic.
A subgroup of the Scientific Advisory Group for Emergencies (Sage) put the R – which represents how many people an infected person will pass the virus on to – at 0.8 to 1.0, down from 1.2 to 1.3 last week.
The latest estimate came as new Government figures showed one in 10 UK adults have now received their first dose of a Covid-19 vaccine.
The Scientific Pandemic Influenza Group on Modelling (Spi-M) said the number of new infections is now shrinking by between 1% and 4% every day.
All regions of England have seen decreases in the R number and growth rate estimates compared with last week, and R is below or around 1 in every region.
However, scientists advising Government warned that case levels “remain dangerously high”.
Professor Sir David Spiegelhalter, from the maths faculty at the University of Cambridge, said the drop in R is “very encouraging news”.
He said the decline in positive cases has been slow but cases are “nearly half what they were three weeks ago, which is enormously hopeful”.
He told the BBC that, by next month, the UK will start seeing the benefits of the vaccine rollout.
Government data up to January 21 shows of the 5.8 million jabs given in the UK so far, nearly 5.4 million were first doses, marking a rise of 409,855 on the previous day’s figures and taking the seven-day rolling average to 306,880 doses per day.
The day-on-day increase saw the average number of first doses needed each day in order to meet the Government’s target of 15 million by February 15 fall for the first time, with the required daily rate now standing at 400,704.
A further 1,401 people had died within 28 days of testing positive for Covid-19 as of Friday, bringing the UK total to 95,981, while another 40,261 confirmed cases were reported.
It comes as data from the Office for National Statistics (ONS) infection survey shows there has been a slight drop in the number of people infected with coronavirus in England after lockdown measures were introduced.
The ONS estimated one in 55 people in private households in England had Covid-19 between January 10 and 16, down from one in 50 people for the Christmas period of December 27 to January 2.
The slight fall comes as the new variant of coronavirus, which is highly transmissible, continues to put pressure on hospitals.
The ONS data is from a random sample of people, with 600,000 tests carried out over the last six weeks, including those with no symptoms.
It does not include care homes, hospitals or other institutional settings.
Sarah Crofts, senior statistician for the survey, said: “In England we have seen a slight decrease in the percentage of people testing positive. However, rates remain high and we estimate the level of infection is still over one million people. The picture across the UK is mixed.”
It comes after a separate study called React, from Imperial College London, found the prevalence of coronavirus across England increased by 50% between early December and the second week of January.
For that study, 143,000 volunteers were tested in England between January 6 and 15, with results showing that one in 63 people were infected.
The new ONS study data estimates that around one in 70 people in Wales had Covid-19 between January 10 and 16 – unchanged from the previous estimate.
In Northern Ireland, the figure was one in 60 people, up from one in 200 for the December period, while the estimate for Scotland was broadly unchanged, up slightly from around one in 115 people for December 25 to 31 to one in 100 for January 10 to 16.
The ONS also found that around one in 35 people in private households in London had Covid-19 between January 10 and 16 – the highest figure for any region in England.
Around one in 40 people in north-east England had Covid-19 during this period, alongside one in 50 in north-west England and the West Midlands.
The other estimates are: one in 55 people in south-east England, one in 60 in the East Midlands, one in 75 in eastern England, one in 80 in south-west England and one in 85 in Yorkshire and the Humber.
It comes as Downing Street said there are “no plans” to go ahead with a proposal to pay £500 to everyone who tests positive for coronavirus in order to increase the number of people abiding by quarantine rules.
Scientific advisers had welcomed the suggestion of more financial support but Treasury sources were adamant the plan will not go ahead, with one telling the PA news agency bluntly: “Won’t happen.”
Some 25% are thought to comply with rules to self-isolate for 10 days after testing positive and 15% continue to go to work as normal.
The Resolution Foundation think tank said the current approach, which it estimates only around 13% of workers are eligible for, is “not fit for purpose”.
In other developments:
– Prime Minister Boris Johnson is due to lead a Downing Street press conference at 5pm.
– Police broke up a wedding attended by around 400 people in a school in Stamford Hill, north-east London.
The ONS data on infection also looked at how many people have had Covid-19.
In some areas of England, as many as one in 20 people in private households are estimated to have had the virus between January 12 and 17.
These areas are Rochdale, West Lancashire, Knowsley, Liverpool and Sefton in north-west England; and Redbridge, Barking & Dagenham, Newham and Croydon in London.