UK’s outbreak is still shrinking by up to 5% a day as SAGE admits R rate could still be above one

Britain’s coronavirus outbreak is still shrinking by up to 5 per cent a day, according to official data released today — but SAGE has warned the R rate could be above one in the South West of England and London. 

The Government’s scientific advisory panel revealed the UK’s current growth rate — how the number of new cases is changing day-by-day — is between minus five and minus one per cent.

It is more confirmation the crisis is still petering out and suggests the reopening of pubs, restaurants, hairdressers and beauty salons on July 4, dubbed ‘Super Saturday’, has not triggered a resurgence yet.

But the figures show the UK’s outbreak is now be shrinking at a slightly slower speed because the growth rate has crept up from last week’s rate of minus 5 per cent to minus 2 per cent per day.

Scientists today said they were ‘cautiously optimistic’ about the data, which they say shows ‘there is no indication the epidemic has gotten out of hand as a result of the easement’ of lockdown.

But they warned Brits ‘must stay completely vigilant’ because a lag in the statistics means it is at least two weeks behind and it could take until next week for any spike to become visible. 

Separate figures released by SAGE today shows the virus’s reproduction rate — the average number of people each Covid-19 patient infects — is still between 0.7 and 0.9 as a whole for the UK, meaning it hasn’t changed in two months.

But SAGE admitted the R could be as high as 1.1 in the South West of England, where Britons have been flocking for stay-cations to enjoy the coastline of Cornwall, Devon and Dorset, and in London, where pubs have been rammed with customers after reopening earlier this month.

For England as a whole, the R is slightly higher than the rest of the country, with the reproduction number hovering between 0.8 and 1. Keeping the rate below one is considered key because it means the outbreak is shrinking as not everyone who catches it passes it on. 

Other data released today from the Office for National Statistics (ONS) said the coronavirus outbreak in England isn’t changing in size and 1,700 people are still catching the illness every day. Estimates based on population testing suggest one in every 2,300 people is now carrying Covid-19 – a total of 24,000 people or 0.04 per cent of the population. This is a slight rise from the 0.03 per cent (14,000) estimated last week.

It comes after Boris Johnson today urged all workers to return to offices in August as he set out his timetable for life in the UK to return to normal by Christmas. In a Downing Street press conference, he revealed restrictions on the use of public transport in England are being dropped immediately with trips on the train and bus to no longer be viewed as the option of last resort.

In other coronavirus developments in Britain today:

• Health Secretary Matt Hancock ordered Public Health England to review the way it counts deaths because of a ‘statistical flaw’ that means officials are ‘over-exaggerating’ the daily toll;
• Security Minister James Brokenshire said the UK is at least ’95 per cent’ certain the Kremlin gave the green light for Russian cyber attacks designed to steal coronavirus vaccine research;
• Britain could already have herd immunity against Covid-19 because so many people have had similar illnesses in the past, an Oxford University study claimed;
• Half a million coronavirus tests made by Randox and used by thousands of Britons were recalled after spot checks revealed they were not sterile.

Reacting to the findings, Dr Daniel Lawson, a statistician at the University of Bristol, said: ‘These data allow us to be cautiously optimistic. There is no indication that the epidemic has gotten out of hand as a result of the easements. 

‘However we must stay completely vigilant because there is a delay of at least two weeks before an increase in the reproductive rate of the virus is visible in the data.’

The growth rate reflects how quickly the number of infections is changing day by day and, as the number of infections decreases, it is a way of keeping track of the virus. 

If it is greater than zero, and therefore positive, then the disease will grow, and if the growth rate is less than zero, then the disease will shrink. 

However, there is some regional variation between the figures. In the East of England, the growth rate changed from minus 4 per cent to plus 1 per cent, to minus 4 per cent to zero. The R number is 0.8-1.0. 

The figures come as beauty salons, outdoor pools and other businesses were allowed to reopen to the public with a further relaxation of lockdown restrictions.

In London, the growth rate is between minus 3 per cent and plus 2 per cent, compared to between minus 5 per cent and plus 1 per cent last week. 

The capital has an R value of 0.8-1.1. The Midlands has a growth rate of minus 5 per cent to minus 1 per cent per day, compared to minus 6 per cent to minus 2 per cent last week. Its R value is 0.7-1.0.

In the North East and Yorkshire, the growth rate is unchanged at minus 5 per cent to minus 1 per cent. Its R number is 0.7-0.9. 

The North West has a growth rate of minus 6 per cent to minus 1 per cent, a change from minus 5 per cent to minus 1 per cent, and an R value of 0.7-1.0. 

The growth rate in the South East is unchanged at minus 4 per cent to zero, with an R value of 0.8-1.0. In the South West, the growth rate changed from between minus 6 per cent and plus 1 per cent, to between minus 6 per cent and plus 2 per cent. 

The region also sees the R value creeping above one, with a range of 0.7-1.1. Across England, the growth rate is between minus 4 per cent and zero, compared with between minus 4 per cent to minus 1 per cent next week. 

The R value across England is 0.8-1.0 and has been that way since jumping from 0.8 to 0.9 last week. 

An R of 1 means the coronavirus spreads one-to-one and the outbreak is neither growing nor shrinking. Higher, and it will get larger as more people get infected; lower, and the outbreak will shrink and eventually fade away.

At the start of Britain’s outbreak it was thought to be around 4 and tens of thousands of people were infected, meaning the number of cases spiralled out of control.

The R has now been between 0.7 and 0.9 since the end of May, according to the Government, but experts say it will start to fluctuate more as the number of cases gets lower.

The fewer cases there are, the greater the chance that one or two ‘super-spreading’ events will seriously impact the R rate estimate, which are at least three weeks behind.

Sir Patrick Vallance, the Government’s chief scientific adviser, explained last month that the UK is approaching the point where the R will no longer be an accurate measure for this reason.

The Scientific Pandemic Influenza Group on Modelling (SPI-M) – a subgroup of SAGE – use data on the number of Covid-19 deaths and positive tests to work out how quickly outbreaks are growing. Monitoring confirmed cases, hospitalisations and deaths is a more accurate way to identify local hotspots, they say.

As the number of people with the virus falls, the data measuring them will be more volatile and affected by small outliers or unusual events. A large margin of error could mean one ‘super-spreading’ event, when one person infects a lot of others, could send the R rate for one area soaring, mathematicians warn.

R rates also fluctuate depending on mobility, and are likely to shoot up when lockdown eases because infected patients will come into contact with more people, on average – especially if they show none of the tell-tale symptoms. But a temporarily high R rate is not necessarily cause for concern if the actual number of infections stays low.

For example, if there are 1,000 people infected with the virus and they all infect 0.8 people each on average, or 800 in total, the R will be 0.8.

But if 995 of them infect 0.8 people each, on average, but five of them don’t realise they are ill and infect 10 people each, there are now a total of 846 extra patients. This means the R rate is 0.846 – a marginal increase.

However, if there are only 10 people with the virus in an area, with nine of them at an R of 0.8, and one of them is a super-spreader and infects 10 others, there are 17 patients from those 10 and the R rate has risen to 1.72.

It comes as Boris Johnson today announced he is aiming for life in the UK to return to something close to normal by Christmas as he said workers will be encouraged to stop working from home from August.

The Prime Minister today used a Downing Street press conference to set out his timetable for the further easing of lockdown measures. 

He said restrictions on the use of public transport in England are being dropped from today with trips on the train and bus to no longer be viewed as the option of last resort. 

He said the Government will publish new guidance applying from August on the crunch issue of working from home in the hope that more employees will physically return to their desks to give the economy a much needed boost. 

He made that pledge despite Sir Patrick Vallance, the Government’s chief scientific adviser, warning yesterday that there was ‘absolutely no reason’ to change the policy.  

Meanwhile, the Prime Minister said the Government is targeting the reopening of stadiums in the autumn with audiences potentially returning to football matches and outdoor gigs in October. 

Crucially, the PM also said the Government is hoping to review all the remaining ‘outstanding restrictions’ in the coming months in order to allow a ‘more significant return to normality from November’ and ‘possibly in time for Christmas’.

However, Mr Johnson insisted that all of the proposed changes would only go ahead if the spread of coronavirus continues to fall and that ‘we will not hesitate at any stage to put on the brakes’ if there is an increase in infections. 

He stressed the UK must be prepared for a second wave in the winter as he announced £3 billion of extra funding for the NHS and vowed new powers to enable ministers and councils to impose strict local lockdowns.

He also pledged to increase the UK’s daily coronavirus testing capacity to 500,000 a day by the end of October with the NHS Test and Trace programme tasked with playing a key role in stopping the spread of the disease.