Ordinary life has been turned on its head for most of us in recent weeks thanks to government measures to keep people apart to try to slow the spread of the coronavirus.
But how do we know if these social distancing measures are working? Are people sticking to the rules, and if they are, will this reduce transmission?
As with so many questions relating to Covid-19, we don’t have definitive answers yet. But there is new research that has sparked cautious optimism on both those fronts.
It’s been made clear from the outset that social distancing will only work if enough people obey the rules.
The modelling from Imperial College which informed the government’s decision to tighten social distancing rules on March 16 said there would be a dramatic drop in new infections if we cut contact with people outside the household, school or workplace by 75 per cent.
This raises an important question: how are officials checking whether people are observing these social distancing guidelines in sufficient numbers?
The government has never given us an answer to this, despite repeated inquiries.
But the chief scientific adviser, Sir Patrick Vallance, said on Monday that there had been a dramatic drop in the use of public transport, footfall in high streets and visits to bars and restaurants, so we know that this is the kind of data officials are looking at.
Now we have a new insight into how people may have reacted to the changes, courtesy of the Centre for Mathematical Modelling of Infectious Diseases at the London School of Hygiene and Tropical Medicine (LSHTM).
The researchers got the polling company Ipsos to do an email survey of 1,356 UK adults about changes to their lifestyles. The sample was representative of the wider population in terms of age, gender, and place of residence.
The surveys were sent out a week ago, after the lockdown was announced.
The first results suggest people have cut social contacts by 73 per cent. That means that on average, we are coming into contact with three people a day instead of about ten, and most of the contact is in the home.
It’s the first academic – though not yet peer-reviewed – study to present evidence of a high level of compliance with the social distancing guidelines (this Savanta survey also finds that most of us are following government advice and are increasingly likely to self-isolate).
The apparently high level of compliance leads the LSHTM researchers to predict that there could be a substantial decline in coronavirus cases in the UK over the coming weeks.
In fact, they estimate that the number of people each contagious person will infect (which scientists call the “R-zero” number) has already dropped below 1.
Scientists say that is the point at which the virus will no longer be able to sustain itself in a population and will gradually die out.
It’s important to note that this is based purely on mathematical modelling – it has not yet been confirmed by real-world results like the number of positive tests for Covid-19.
We are not likely to get proof of whether the latest distancing measures have really worked for weeks, because there are delays between people becoming infected and getting into hospital – which is where nearly all the coronavirus tests take place.
That means recorded Covid-19 cases and deaths reported today usually involve people who caught the disease several weeks ago.
Nevertheless, expert reaction to the study has been cautiously positive, and this adds to the optimism some scientists already feel about an apparent slowdown in the rate of new confirmed coronavirus cases being added to the tally each day in the UK.
Responding to the LSHTM study, Professor Keith Neal, Emeritus Professor of the Epidemiology of Infectious Diseases at the University of Nottingham, said: “Given the flattening in new cases and (the fact that) we have some measures in place now for over two weeks and a type of lockdown for over two weeks, their conclusion that R-zero may be below 1 is credible.
“Once R-zero is below 1 the epidemic cannot sustain itself as each case produces less than one new case and the epidemic eventually ceases.
“This does not provide any evidence for how long we need to continue lockdown but similar studies could be done to look at the social mixing patterns if they are partially relaxed.”