Coronavirus infections fell by almost a third in England during the second national lockdown, research suggests.
There was a 30% drop in cases across the country over almost a fortnight this month, the latest interim findings from Imperial College London’s React study showed.
Regionally, the research suggests infections fell by more than half in the North West and North East, and were also down in Yorkshire and the Humber.
But prevalence remained high in the East Midlands and West Midlands.
More than 105,000 volunteers were tested in England for the ongoing research.
England’s second lockdown began on November 5 and is due to end on December 2, when the country will go into tiered restrictions.
Professor Paul Elliott, director of the programme at Imperial, said the findings suggest the tiers before the beginning of November, followed by the lockdown, had helped bring cases down.
He said: “Our robust data offers encouraging signs for England’s epidemic, where we’re seeing a fall in infections at the national level and in particular across regions that were previously worst affected.
“These trends suggest that the tiered approach helped to curb infections in these areas and that lockdown has added to this effect.
“As we approach a challenging time of year, it’s even more vital that, through our actions and behaviours, we all play our part in helping to keep the virus at bay.”
The Department of Health said the research supports findings from the Scientific Advisory Group for Emergencies (Sage) that stronger measures would be needed in some areas to prevent the epidemic from growing and that local tiers should be toughened to keep the virus under control when the lockdown ends this week.
He said: “Thanks to the huge efforts of the public over the last few weeks, we have been able to get the virus more under control.
“This latest data shows we must keep our resolve and we cannot afford to take our foot off the pedal just yet, despite the encouraging fall in cases and progress on vaccines.
“The next few weeks and months are the busiest time of year for our NHS, so it’s vital we all continue to follow new local restrictions, wash our hands, wear a face covering and observe social distancing.”
Steven Riley, professor of infectious disease dynamics, Imperial College London, added: “I think it is reasonable to say that both by preventing some regions accelerating, and by increasing the speed of decline in the most prevalent areas, this is good evidence that the lockdown was effective.”
On Christmas, Prof Elliott said: “If it is increasing contact, there’s more chance of transmission, and therefore there’s more chance that the virus will spread and clearly that’s a very limited period.
“Over that limited period, it probably won’t make a huge difference to the R value.
“But if there is more transmission then there will be more virus.”
Prof Riley said: “I would say my own concern is more about the period between from the end of lockdown to the beginning of that Christmas period … that’s a longer period of time.”
Prof Elliott explained: “If the prevalence goes up in this next period then you’re going to go into that Christmas period with a higher chance of transmission.”