Several new studies released on Friday suggested a rapid rise in coronavirus infection is slowing in England, though experts urged caution in concluding that the government’s recent restrictions were successfully suppressing the epidemic.
The weekly coronavirus infection survey by the Office for National Statistics estimated that between September 18-24, the most recent period of study, there were 8,400 new infections per day in England. The figure for the previous week was 9,600 new cases per day.
Another large infection survey, led by Imperial College London, used different sampling methods and came to a similar conclusion on Thursday.
Katherine Kent, co-head of analysis for the ONS Infection Survey, said: “While the evidence suggests that the increase in new cases may be levelling off after a sharp rise in August and September, it is too early to be certain at this stage.”
Results from a third survey, the Covid Symptom Study by King’s College London, also provided evidence of a slowing of infection rates.
“We are confident that this flattening in the data looks real and that this might be an early sign of infection rates slowing down,” said Tim Spector, professor of genetic epidemiology at King’s. “This may be due to a number of factors, including social distancing and the rule of six.”
Public Health England’s weekly surveillance report, pulling together coronavirus data from numerous sources, came to a similar conclusion. “There are some small signs that the recent measures introduced may be having a positive effect, however it is far too early to say,” said Paul Johnstone, PHE national director for place and regions.
He added: “Therefore it is essential everyone continues to remain alert to control the virus by social distancing, washing hands regularly and wearing a face covering when needed and following the guidance if you live in an area with additional restrictions.”
Less encouraging, however, was a set of figures released on Friday by the Government Office for Science. Drawing on the expertise of its advisory group Sage, it estimated that R, the average number of people infected by someone with the virus, is between 1.3 and 1.6 for the UK as a whole and between 1.2 and 1.6 for England. Last week Sage put R at between 1.2 and 1.5 for the UK.
The Imperial College and King’s College studies estimated R at 1.1 and 1.2 respectively for England.
“While there are some early indications suggesting that the growth of the epidemic might be slowing, Sage urges caution and believes it is too early to draw firm conclusions,” the government said. “More data are needed to accurately assess any recent changes in transmission and it is still highly likely that the epidemic is growing exponentially across the country.”
Kevin McConway, emeritus professor of applied statistics at the Open University, said discrepancies between the studies were to be expected because “there’s quite a lot of statistical uncertainty about all these estimates”.
“It is important to point out that none of these reports are saying that numbers of infections are now shrinking — only that the numbers may be growing more slowly than they were a couple of weeks ago,” he said.