The estimated coronavirus “R number” range has risen above one in parts of England, the government has confirmed.
The overall R rate across the UK remains between 0.7 and 0.9, while across England it is 0.8-1.0, according to the Scientific Advisory Group for Emergencies (Sage).
However, regional values for R across England, which have been published for the first time, show that the South West has an R rate of between 0.8-1.1.
An R number of above 1 means the COVID-19 outbreak is growing in that area.
Speaking at the Downing Street press conference on Friday after the data had been released, transport secretary Grant Shapps sought to allay concerns about the R value in the South West.
He said a high and a low estimate, based on a number of modelling approaches taken by Sage, meant “it so happens that one of them says it could be between 0.9 and 1.1”. He described it as an “outlier” of the central estimate.
Asked about the possibility of a regional lockdown if one area continues to increase, he told the briefing: “I wouldn’t want to rule anything out.”
NHS England medical director Professor Stephen Powis added: “R is of course a very important way of looking at this but there are other things that we look at.”
But he said the ONS surveillance study showed a “steady reduction” in the number of infections in the community.
“And really that evidence also suggests the R value is below 1 because it is only when the R value is below 1 that we would see that decrease in infections,” he added.
Prof Matt Keeling, professor of populations and disease at the University of Warwick, said it was difficult to compare regions because they overlapped, meaning it is difficult to say that any one region is worse than any other region.
“All the ranges are closer to the critical threshold of R=1 than we would ideally like to see – which means that the epidemic is declining relatively slowly.
“This also means we haven't got much wiggle room for additional relaxation of social distancing measures.”
The news comes as ONS figures found the outbreak is continuing to decline in England, while non-essential businesses are also due to reopen on Monday.
Chief scientific adviser to the government Sir Patrick Vallance said on Wednesday that changes to anti-coronavirus measures would have to happen “slowly” and their impacts measured.
“The epidemic is shrinking, but not fast. Numbers are coming down but are not yet very low,” he said at the Downing Street press briefing on Wednesday.
The South West of England has the highest R range, from 0.8 – 1.1, and the East of England is the lowest, ranging from 0.7 – 0.9.
London, the Midlands, the North West and the South East all have R between 0.8 and 1, while Yorkshire and the North East have a value of 0.7 – 1.
Much of the focus during lockdown was about keeping R down below 1, which means the outbreak would be in retreat in the UK.
Prof Keeling said R warned become less useful as the outbreak declines and added: “There is still some uncertainty in these values, which are influenced by the three interacting outbreaks in hospitals, in care homes and in the community.
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“Having input from multiple groups using a variety of methods and data streams helps to overcome these issues.
“As the number of cases becomes smaller in many regions, these predictions will become more uncertain and more biased by small localised outbreaks.
“These are not a measure of risk, they are about the decline of the epidemic.
“To understand risk you need to look at both the incidence of infection and individual behaviour.”
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