The government is under pressure to bring in tougher local lockdowns in some areas, as a new study showed the R value was rising across England and had tipped above 1 in the north-west for the first time since the peak of the coronavirus epidemic.
The development raises concerns that a return to stricter physical distancing may be needed in some areas and that the UK could continue to see hundreds of daily deaths for weeks.
The influential model, from scientists at Public Health England (PHE) and the University of Cambridge, puts R at 1.01 for the north-west and 1 for the south-west. The north-west – including Liverpool and Manchester – is viewed as particularly concerning due to higher numbers of infections there, which would be projected to continue at the current rate.
Regional leaders said they feared the prospect of a second spike in deaths and that the decision to ease lockdown based on the national picture – ignoring regional hotspots – had been a mistake.
However, Matt Hancock, the health secretary, attempted to downplay the new study from Cambridge and PHE, which is part of his own department. He insisted it was right to ease the lockdown and claimed that the government’s overall view after looking at various studies was that the R value was still below 1 in all regions.
Appearing at No 10’s daily press briefing without the usual scientific experts alongside him, Hancock defended himself against an accusation that the government was “cherrypicking” good data in order to justify loosening restrictions.
R, or the 'effective reproduction number', is a way of rating a disease’s ability to spread. It’s the average number of people on to whom one infected person will pass the virus. For an R of anything above 1, an epidemic will grow exponentially. Anything below 1 and an outbreak will fizzle out – eventually.
At the start of the coronavirus pandemic, the estimated R for coronavirus was between 2 and 3 – higher than the value for seasonal flu, but lower than for measles. That means each person would pass it on to between two and three people on average, before either recovering or dying, and each of those people would pass it on to a further two to three others, causing the total number of cases to snowball over time.
The reproduction number is not fixed, though. It depends on the biology of the virus; people's behaviour, such as social distancing; and a population’s immunity. A country may see regional variations in its R number, depending on local factors like population density and transport patterns.
Hannah Devlin Science correspondent
“The [PHE/Cambridge] study you mentioned is one, but the overall assessment that is brought together by Sage that advises the chief medical officer is the one that I look at,” he said. “What I do is look at all of these different studies and the overall view of Sage is that the R is between 0.7 and 0.9 and it is higher in the south-west of England and the north-west but it remains below 1 in each area. That doesn’t take away from the need that we spot and crack down on localised outbreaks.”
The government’s scientists have consistently said the lockdown can only be eased if the R rate – showing the average number of people to whom one infected person will pass the virus – remains below 1. If it is higher, that suggests exponential spread of the virus.
However, separate figures from the Office of National Statistics suggested there was a halving in the number of people infected across England in the second half of May – although this data did not take into account infections in care homes and hospitals.
In their latest analysis, the Cambridge-PHE team conclude that R has risen in all regions and is hovering just below or around 1, “probably due to increasing mobility and mixing between households and in public and workplace settings” and that based on current estimates, the decline in daily deaths could be arrested by mid-June, at which point there could still be hundreds of deaths a day.
Paul Birrell, of PHE, said: “More worrying is the north-west where the infections are coming up the highest in absolute number, where there are 4,000 [daily infections] but again there’s quite a large band of uncertainty attached to that.”
Birrell said that an R number of about 1, or above, was “not necessarily a cause for immediate concern” but that further investigation was needed to identify hotspots within the north-west.
The model draws on death rates, meaning it has a built-in lag and does not capture any additional impact of the easing of lockdown this week. It is one of several that feeds into the government’s official estimate of R, which on Friday was between 0.7 and 1, a slight increase on last week’s figure. A separate analysis by the London School of Hygiene and Tropical Medicine’s modelling team also put the R-value at 1 in in the south-west, but gave a lower value of 0.8 for the north-west.
At his weekly press conference on Wednesday, Andy Burnham said weekly cases in Greater Manchester were at their lowest since the start of lockdown, with 190 new positive Covid-19 diagnoses. But there were some “worrying” statistics: there had been a slight increase in Covid-19 hospital admissions and those in intensive care.
Burnham told Sky News: “I’m sure that people across the north-west will be looking at this new information and feeling quite anxious about it. ”
“I think the lockdown was relaxed prematurely and if you combine with that the loss of confidence in the government’s public health messaging with everything that came out of the Dominic Cummings situation, I think this is the situation we are now in.”
Steve Rotheram, the mayor of the Liverpool city region, said lockdown was eased too quickly by a London-centric government.
He said: “When the infection rate was at its highest in London and it wasn’t as high here, the government locked down in the interests of the country. The government seem to me to be reopening or unlocking the economy or certainly relaxing the restrictions when it might not be in the interests of the whole country.”
Graham Stringer, a member of the science and technology committee and MP for Blackley and Broughton, said the government had made a fundamental error by concentrating on the national R rate.
The ONS snapshot infection survey, covering the last two weeks in May, found that during that period, an estimated 53,000 people were infected at any time. This puts the daily infection rate at 5,600 compared with almost 8,000 in last week’s figures. Peter Benton, the director of population and public policy operations at the ONS, said: “That, we think, is a real reduction in the number of people being infected.”
Previously, the ONS had said the trend looked flat and stable, but as more data has accumulated a downward trend is now evident, the analysis said.