Coronavirus R rate remains steady as Sage urges public to ‘remain vigilant’

R, which refers to the number of people that an infected person will pass the virus on to, is between 1.2 and 1.3 across the UK, according to the figures released on Friday by the Government Office for Science and the Scientific Advisory Group for Emergencies (Sage).

An R value above 1 indicates the epidemic is still growing, and this week’s estimates mean that, on average, every 10 people infected will infect between 12 and 13 other individuals.

The Sage scientists said: “The latest figures show that we need to remain vigilant to keep this virus under control, to protect the NHS and save lives.

“We all need to play our part and if everyone continues to follow the rules – we can expect to drive down the R number across the country.”

Last week, R was between 1 and 1.4 for the UK as a whole.

Commenting on the figures, Kevin McConway, emeritus professor of applied statistics at The Open University, said: “Probably the most important change in the range for the UK R number this week, compared to last, isn’t that it’s gone up or down, but that it has narrowed a lot.

“This week’s interval is 1.2 to 1.3, which is as narrow as it ever gets.

“That shows that Sage and its advisers are much more confident than they were last week about the national R value.”

However, the estimates provided by Sage are based on data available up to January 11 and do not take into account the events in the last few days.

But Prof Conway added: “Provided case numbers do keep moving in the direction that they have been moving recently, the R number and growth rate should fall over coming weeks – but that might not happen unless people continue to comply with the restrictions.”

Meanwhile, Sage estimates the R value in England to be between 1.1 and 1.3.

The experts said areas that have been under tougher restrictions for a longer period of time – including East of England, London, and the South East – are showing “a slight decline in the number of people infected”.

But they warned that regions such as the North West and South West continue to see infections rise, where the spread of the new UK variant may be playing a role.

Elsewhere, Cambridge University researchers have said the R is below 1 in the East of England, London, the South East, West Midlands and Yorkshire and the Humber.

But they believe it is still above 1 in the South West, North West, North East and the East Midlands, indicating case numbers are growing in those regions.

The Zoe Covid Symptom Study UK Infection Survey from King’s College London puts the UK R rate at 0.9.

It showed that cases have also plateaued in most age groups.

Graham Medley, professor of infectious disease modelling at London School of Hygiene & Tropical Medicine, said the reason why R estimates from Cambridge and the Zoe app are different to the Government’s is because each of them are using different data streams.

He said: “None of them (the estimates) are ‘wrong’ – they are just different views of the same process.

“Similarly none of them are ‘right’.

“We cannot tell just by looking at the models individually which is right and which is wrong.

“This is why people often combine model results.”

He added: “The approach taken by SPI-M (the modelling sub-group of Sage), and its estimates have been a robust measure throughout the epidemic.

“With the more recent development of data dashboards and other data analytic tools, the weekly publication of an official R value has become less critical in the past months.”

It comes as Public Health England (PHE) released data on Thursday showing that infection rates had fallen in most regions of England across all age groups apart from the over 80s.

At the same time, however, the PHE surveillance report noted that there were more people being admitted to hospitals and intensive care units.

NHS England data shows that around one in five major hospital trusts in England had no spare adult critical care beds on January 10.