The spread of coronavirus did not decline during the first week of England's third lockdown, a study has shown.
The latest React study, from Imperial College London and Ipsos Mori, states that during the initial 10 days of the third Covid-19 lockdown in England, "prevalence of coronavirus was very high with no evidence of decline".
Researchers also found that the prevalence of Covid-19 across England increased by 50% between early December and the second week of January.
Volunteers tested positive between January 6 and 15
After testing more than 142,900 volunteers in England between January 6 and 15, they found that one in 63 people were infected.
The report, which researchers said does not yet reflect the impact of the national lockdown, also showed there were “worrying suggestions of a recent uptick in infections”.
National prevalence of the virus increased by half, from 0.91% in early December to 1.58%, the latest React study showed.
While there was a rise in prevalence across all adult age groups, it was highest in 18- to 24-year-olds, and more than doubled in the over 65s age group.
London saw the highest regional prevalence, jumping from 1.21% to 2.8%, while there were also rises in the south east, east of England, West Midlands, south west and north west.
The only region to see a decrease was Yorkshire and the Humber, and prevalence remained stable in the East Midlands and north east, but the researchers warned infection numbers are still high even in these areas.
Additionally, they found large household sizes, living in a deprived neighbourhood, and areas with higher numbers of black and Asian individuals were associated with increased prevalence.
Key workers, such as healthcare and care home staff, were also more likely to test positive compared to other workers
The study authors said the national R value – referring to the number of people that an infected person will pass the virus on to – was estimated at 1.04.
For the first time the report has mobility data, showing peoples’ movement decreased at the end of December and increased at the start of January, which the scientists said helps to explain the change in prevalence.
Listen to ITV News' coronavirus podcast
Professor Paul Elliott, director of the programme at Imperial, warned that if prevalence continues to be so high “more and more lives will be lost”.
He said: “Our data are showing worrying suggestions of a recent uptick in infections which we will continue to monitor closely.
“To prevent our already stretched health system from becoming overwhelmed, infections must be brought down; if prevalence continues at the high rate we are seeing then hospitals will continue to be put under immense pressure, and more and more lives will be lost.
“We all have a part to play in preventing this situation from worsening and must do our best to stay at home wherever possible.”
Steven Riley, professor of infectious disease dynamics at Imperial, told Times Radio the study had examined a long enough time period to assess the current lockdown.
“It’s long enough that, were the lockdown working effectively, we would certainly have hoped to have seen a decline,” he said.
He said data from previous lockdowns did show a fall, adding that the current research “certainly doesn’t support the conclusion that lockdown is working”.
On what he expects would happen in the current lockdown, he said: “We would expect a similar plateau, a very gradual increase (of infections), if behaviour stays the same and, if our interpretation is correct, if what we are seeing is kind of the result of the post-Christmas period behaviour.”
Health Secretary Matt Hancock said the findings show “why we must not let down our guard over the weeks to come”.
He added: “Infections across England are at very high levels and this will keep having a knock-on effect on the already significant pressures faced by our NHS and hospitals.
“It is absolutely paramount that everyone plays their part to bring down infections.”