Coronavirus: Infection rate in England ‘slowing down,’ major study suggests

The R rate of Covid-19 transmission in England is estimated to have fallen to about 1.1, according to a new major study, suggesting efforts to control the virus could be working.

Although the prevalence of the disease remains much higher than it was at the end of August, there are signs that growth in the infection rate is slowing, research from Imperial College London (ICL) and Ipsos Mori has shown.

More than 80,000 volunteers were tested in England between 18 and 26 September as part of the country's largest study into the virus.

The study is examining levels of infection in the general population by testing more than 150,000 participants over a two-week period each month.

Interim results from the study’s fourth report, which has not yet been peer-reviewed, show around 55 people per 10,000 tested positive, an increase on 13 people per 10,000 in the previous study.

This implies 411,000 people in England had the virus between 18 and 26 September, meaning more than one in 200 people were likely to have been infected at any one time.

The reproduction R number - the rate of transmission throughout the population - has decreased from 1.7 to 1.1, but with a wide possible range of 0.7 to 1.5, the study said.

This suggests that the rate of new infections has decreased, but an R above 1 means cases will still continue to rise if current trends continue.

Scientists called for caution over the findings, noting there was “considerable uncertainty” surrounding the latest R rate estimation.

Professor Paul Elliott, director of the programme at ICL’s School of Public Health, said: "While our latest findings show some early evidence that the growth of new cases may have slowed, suggesting efforts to control the infection are working, the prevalence of infection is the highest that we have recorded to date.

"This reinforces the need for protective measures to limit the spread of the disease and the public's adherence to these, which will be vital to minimise further significant illness and loss of life from Covid-19."

The prevalence of infection was highest among those aged between 18 and 24 - with one in 100 people infected - while cases increased seven-fold in those aged over 65 from 0.04 per cent to 0.29 per cent compared to the last report.

The study also found people of Asian and black ethnicity were twice as likely to have the virus compared to white people.

Half of the volunteers did not have symptoms at the time of testing or the week before, but not all of those people remained asymptomatic throughout, researchers said.

Kelly Beaver, managing director of public affairs at Ipsos Mori, said: "The continuing support of the public by taking part in the study is something we remain immensely grateful for.

"The number of participants gives this study the robustness and thoroughness which marks it out as world leading.”

The findings come after prime minister Boris Johnson pleaded with Britons to obey the rules imposed to tackle a rapidly accelerating second wave, with more than 7,000 new cases of Covid-19 reported in each of the last two days.

Additional reporting by PA