Covid-19: University of Cambridge experts’ warning over R rate in run-up to Christmas
The pattern of the Covid-19 pandemic is “highly uncertain” in the run-up to Christmas, according to University of Cambridge experts.
And they warn that the R rate is likely to be above the all-important one number in the East of England, London, South East and South West, meaning infection numbers will be growing in those areas.
It is thought to be highest in the East of England, which includes Cambridgeshire.
The MRC Biostatistics Unit Covid-19 Working Group at the university examines a range of public health and survey data to examine the rate of infection and forecast what is likely to happen in the coming weeks.
The unit’s latest estimate suggests the number of daily Covid-19 infections in England is currently about 58,800, with 95 per cent likelihood that the number lies between 40,900 and 81,800.
The researchers note that the daily number of new infections is particularly high in the Midlands regions (7,700 and 9,710 infections per day in the East and West, respectively), London (12,000) and the South-East (7,900), although a substantial proportion of these daily infections will be asymptomatic.
The statisticians predict that the number of daily deaths is likely to be between 305 and 531 on December 28.
The R rate (Rt) - which measures how many people an infected person passes on the virus to - is thought to be close to one in most regions.
The probability of it exceeding one is above 80 per cent in London, the East of England, South East and South West, while it is less than 10 per cent in the North East .
“We can be certain that Rt is lower than one in Yorkshire and Humber and North West,” says the unit’s report.
The number of infections nationally has stabilised, they say.
“However, there is still evidence of continued growth in South East and South West, East of England and London, while we confidently estimate we are beyond a second peak in infections in the North West, North East and Yorkshire and Humber.”
“London, followed by the North West, continues to have the highest attack rate, that is the proportion of the population who have ever been infected, with 20 per cent and 18 per cent respectively. The South West continues to have the lowest attack rate though this has been revised upwards to six per cent.”
The unit adds: “The lower values of Rt and the decrease in the number of new infections are likely to be resulting from the combination of social distancing interventions, half-term school closures as well as the most recent lockdown.”
However, looking ahead to the Christmas period, there remains uncertainty over what will happen, due to the volatile picture across the country.
Lead researcher Professor Daniela De Angelis, MRC investigator and deputy director, said:
“The different trends in the number of deaths and number of infections amongst the regions make interpretation of the current situation uncertain.
“The total number of new daily infections has been revised upward from our previous report to around 59,000.
“The volatility in this estimate primarily arises from these differing trends as well as the clustering of Rt values around 1.
“The estimated trends are likely to be the result of the complex interplay of the effects on transmission of the social restrictions introduced in October, the temporary decrease in activity over the half-term period, and the recent lockdown, though the impacts of the latter now appear to have been quite modest.
“The relative impacts of the lockdown compared to the new tiering measures cannot yet be estimated, and this makes any projections of how the pandemic will evolve in the run-up to Christmas highly uncertain. We will continue to monitor the situation closely.”