Britain could exit the coronavirus lockdown by relaxing restrictions on more than half of the population and beefing up protection for those over 70 and vulnerable people, scientists have said.
The strategy from researchers at Edinburgh University, known as “segmenting and shielding”, is intended to create leeway for ministers to ease the lockdown on those least at risk from the virus while ensuring that vulnerable people only come into contact with carers and family members who are free from infection.
The Edinburgh proposal, which has been submitted to ministers, could see millions of people afforded more freedom to move around and return to work while protecting older people and those with underlying health problems to prevent a surge of new infections from overwhelming the NHS.
Ministers are cautious about the idea of extending the lockdown for people over 70 while giving more freedom to younger people because Tory MPs are unhappy with the idea and campaign groups argue that it amounts to discrimination. The former Conservative leader Iain Duncan Smith said: “A lot of people over 70 are fit and have kept themselves fit, often more so than people of other ages. There has been a backlash and people don’t think it’s the right way to go about it.”
However, it emerged on Tuesday that the government’s scientists in March modelled an extended lockdown of 17 weeks for older people compared with eight to 13 weeks for the rest of society, as part of their advice on how to contain coronavirus.
Papers newly released by the Scientific Advisory Group for Emergencies (Sage) showed it looked at the impact of a 17-week lockdown for those either over 65, over 70 or over 80. It said the outcome for a longer lockdown for people over 70 was a reduction in deaths of up to 35% – or up to 50% if combined with other measures such as isolation of those showing symptoms and their households.
Ministers are understood to have considered the idea of different rules for older people, and Matt Hancock, the health secretary, did not rule it out when pressed about the idea on Tuesday. A spokesman for No 10 also said this week it was “perfectly reasonable that we will look at how guidance will apply for different age bands and we’ll continue to be guided by the science”, and stressed that there was a higher risk of coronavirus having a more serious impact for people as they got older.
The government is expected to announce on Thursday that the lockdown will have to continue for the time being. Boris Johnson will set out plans for the next phase of tackling the virus on Sunday, including how restrictions could be lifted when it is safe to do so. The first secretary of state, Dominic Raab, has said the next phase should be “more comfortable, more sustainable” for the public.
Downing Street confirmed on Tuesday that restrictions on outdoor activities were likely to be lifted first. “There is less likelihood of transmission of disease outdoors than indoors, and that is something we will be considering as part of the review,” the prime minister’s official spokesman said.
The Edinburgh proposal could provide a plan for how different age groups or sections of society with different risk profiles could be treated. In a study outlining the strategy, the researchers describe a number of scenarios where the measures come into force over a three-month period.
In one scenario, the most vulnerable 20% of society only come into contact with a further 20%, the shielders, who are made up of healthcare workers and family contacts. Ideally, the shielders would be tested for coronavirus every day they intend to be in contact with vulnerable people.
With the measures in place, restrictions could be relaxed for the remaining 60% of society, though physical distancing and hand hygiene would still be needed to prevent the reproductive rate of the infection, R, rising so high it sets off a second uncontrolled outbreak.
Q&AWhat does the 'R' number of coronavirus mean?
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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 strategy works by concentrating efforts to control Covid-19 in the segment of the population that most needs protecting,” said Mark Woolhouse, a professor of infectious disease epidemiology at Edinburgh University.
“Rather than a blanket strategy, we have one that focuses on protecting those where the public health need is greatest. It’s a nasty disease and we want to control it as much as we can, but it’s not so nasty in 80% of the population that we’d ever have contemplated locking down the whole country to control it,” he said.
Woolhouse stressed that the approach was not a magic bullet, adding that it would need to be combined with contact tracing and other measures to allow Britain to ease some of its lockdown restrictions. As scientists learned more about who was most vulnerable to the virus, the number of people who needed shielding could be reduced, he said.
Woolhouse, who said he was speaking as an independent scientist, is a member of the UK government’s scientific pandemic influenza group on modelling (Spi-M), which is chaired by Prof Graham Medley, a co-author on the paper. Medley was one of the first scientists to discuss how the population might acquire “herd immunity” as the epidemic swept through the country. The work has been peer-reviewed by the Royal Society’s newly formed Rapid Assistance in Modelling the Pandemic (Ramp) group.
Sarah Harper, a professor of gerontology at Oxford University, who was not involved in the research, raised concerns about considering all people over 70 as vulnerable, even if that changed over time. “Using chronological age without taking into account individuals’ health conditions will confine healthy, active, older individuals to their homes,” she said.
“Easing lockdown might be more effective if the risks were explicitly explained to the population, the possible range of vulnerabilities highlighted and individuals asked to take appropriate action. These are sensible public health approaches which might have a better chance of being complied with,” Harper added.