CASE LOAD
2
THE crucial coronavirus “R” infection rate may have risen over the last week, Government advisors today warned.
Experts estimate that the dreaded Covid-19 reproduction number has gone up from between 0.5 and 0.9 to between 0.7 and 1.
⚠️ Read our coronavirus live blog for the latest news & updates
2
It comes just days after some lockdown measures were eased - including urging those who can't do their jobs from home to return to work.
But the government's top scientists cautioned that the small increase in the R value isn't thought to be linked due to a lag of about two to three weeks in data.
Instead, they believe that as the total number of cases in the community is falling, the number in care homes and hospitals is accounting for a greater proportion of the total.
The new R rate estimate was based on the latest modelling by a sub-group of the Scientific Advisory Group for Emergencies (SAGE).
It's based on data such as contacts, hospital admissions, ICU admissions and deaths, which generally takes 2-3 weeks for changes in R to be reflected due to the time between infection and needing hospital care.
Therefore there is no real-time figure for R, as it reflects the situation around three weeks prior.
Vital rate
The R value is the average number of people from which one infected person can spread the virus.
It can indicate whether the epidemic is getting bigger or smaller - if it's above 1 it's seen to be growing, and less than 1 suggests the epidemic is shrinking.
At the peak of Britain's outbreak, the number is thought to have reached 3 and the country was forced into lockdown.
The strict 'stay at home' measures saw that pushed down to a range below 1 - varying in different regions.
Research published yesterday by Public Health England and Cambridge University had suggested the R number in the capital - where cases peaked in early April - had fallen to 0.4.
They also found the North West also has one of the highest "R" infection rates in the country.
But the country's top scientists today cautioned that the value has gone back up since last week and the range is now somewhere between 0.7 and 1.
However SAGE is confident that overall the R is not above 1, meaning the number of infections is not increasing and is very likely to be decreasing.
Asked about the R rate at today's Downing Street brief, Deputy chief medical officer Dr Jenny Harries explained: "There's quite a range there, 0.7 to one, in the estimate of 'R' and this is for a number of reasons.
"Partly because a number of different models are used to model this data and it's important that they challenge each other and that we get the consistency of that.
"Partly, the data comes from historic data. Obviously we can't predict precisely so we're estimating it on different sources of information so things like hospital admissions that have happened historically.
"And then I think thirdly importantly, we know that we have slightly different 'R' values relating to some areas of risks.
"So obviously in recent weeks, care homes have been heightened interest, hospitals also and we keep an eye on those. So this is very much a national average."
What is the R rate?
R0, or R nought, refers to the average number of people that one infected person can expect to pass the coronavirus on to.
Scientists use it to predict how far and how fast a disease will spread - and the number can also inform policy decisions about how to contain an outbreak.
For example, if a virus has an R0 of three, it means that every sick person will pass the disease on to three other people if no containment measures are introduced.
It's also worth pointing out that the R0 is a measure of how infectious a disease is, but not how deadly.
On Sunday, Boris Johnson said that the R rate was between 0.5 and 0.9 - but urged the British public to help keep it below 1.
In his address to the nation, he said: "It depends on all of us – the entire country – to follow the advice, to observe social distancing, and to keep that R down."
He added: "We must make sure that any measures we take do not force the reproduction rate of the disease - the R - back up over one so that we have the kind of exponential growth we were facing a few weeks ago."
Sir Patrick Vallance, the Government's chief scientific adviser said: “R is one of the important things you can track to understand an epidemic.
"If you can estimate R, then you have part of a reliable tool for planning how to combat the virus.
“If the R is higher than one that means this disease is growing exponentially and will keep on spreading to more and more people.
"To keep R below one and control the virus, it is vital that people stay alert and continue to follow the latest Government guidelines to the letter.
“In the coming weeks, we will update this estimate regularly.”
Balancing act
Ministers have been faced with a balancing act between keeping the R value and death rate down - and ensuring that Britain's economy does not totally collapse.
The PM made only small tweaks to the lockdown rules this week when people were encouraged to return to work if they couldn't do their job from home.
Unlimited exercise was also put back on the cards while individuals are now free to meet one person from another household at a safe distance outdoors in a park.
But Mr Johnson warned that stricter measures could be rolled out again if needed.
Scientific experts have been advising the Government on how each option for unlocking the country could affect the R value.
MORE ON CORONAVIRUS
Around one in three Brits - 17.3million people - may already have been infected with coronavirus, experts say.
The World Health Organisation (WHO) estimated at the start of March that the coronavirus R value stands somewhere between 2 and 2.5.
In comparison, the seasonal flu is estimated to be roughly 1.3 while measles has a reproductive value of between 12 and 18.
The Sun Says
WHY are we being governed by an “R” infection rate that includes care homes?
As tragic as their death toll is, they skew this crucial figure and the public perception of the risk to everyone else. That will be lower than the overall rate — and is said to be substantially so in London.
The apparently rising “R” released yesterday reflects restrictions three weeks ago, has nothing to do with the lockdown being eased . . . and includes care homes and hospital infections.
This matters, for millions of workers. And for teachers, whose risk from returning to school is being exaggerated by their unions even though it is statistically tiny, as Deputy Chief Medical Officer Jenny Harries says.
Our tentative steps back to freedom, back to work and towards rebuilding our economy must not be delayed by how many old folk are still catching the virus in care, as heartbreaking as that is.
CORONAVIRUS CRISIS - STAY IN THE KNOW
Don't miss the latest news and figures - and essential advice for you and your family.
To receive The Sun's Coronavirus newsletter in your inbox every tea time, sign up here.
To follow us on Facebook, simply 'Like' our Coronavirus page.
Get Britain's best-selling newspaper delivered to your smartphone or tablet each day - find out more.
Coronavirus is killing a greater proportion of people in poorer areas, shocking figures show