New modelling suggests that social distancing measures like the ones announced by the government today could prevent hundreds of thousands of deaths from the Covid-19 virus.

Research from Imperial College London published today models what might happen if countries did nothing to try to prevent the spread of the coronavirus: more than half a million deaths in Great Britain.

Measures aimed at slowing but not stopping the spread of the virus could cut the number of deaths to around a quarter of a million.

Only more drastic “suppression” measures like social distancing of the entire population – one of the measures announced by Prime Minister Boris Johnson today – will cut deaths to tens of thousands of deaths instead of hundreds of thousands, depending on different variables.

The scientists at the MRC Centre for Global Infectious Disease Analysis at Imperial concluded that: “Suppression will minimally require a combination of social distancing of the entire population, home isolation of cases and household quarantine of their family members.”

The government is advising everyone to stop non-essential contact with other, stop all unnecessary travel, work from home and avoid social venues and large gatherings.

For the modelling on widespread social distancing to hold true, the researchers say all households will have to reduce contact outside the household, school or workplace by 75 per cent and cut workplace contact rates by 25 per cent.

Mr Johnson said it was particularly important for people over 70, for pregnant women and for people with certain health conditions to avoid unnecessary social contact.

He said that by this weekend, people with the most serious health conditions would be “largely shielded from social contact for around 12 weeks”.

The government advice is also for people to isolate themselves for 14 days if they or anyone in their household has a high temperature or a new and continuous cough.

School closures

The government has stopped short of closing schools and colleges so far, unlike a number of other countries.

The new modelling suggests that closing schools could save significant numbers of lives, but experts have previously warned that the measure could end up being counter-productive if it forces large numbers of parents employed by the NHS to stay at home.

The authors said the measures announced today “may need to be supplemented by school and university closures, though it should be recognised that such closures may have negative impacts on health systems due to increased absenteeism”.

The modelling was carried out by scientists at the MRC Centre for Global Infectious Disease Analysis at Imperial College.

One of the authors, Professor Neil Ferguson, said: “Here we provide concrete estimates of the scale of the threat countries now face.

“We use the latest estimates of severity to show that policy strategies which aim to mitigate the epidemic might halve deaths and reduce peak healthcare demand by two-thirds, but that this will not be enough to prevent health systems being overwhelmed.

“More intensive, and socially disruptive interventions will therefore be required to suppress transmission to low levels.”

Alternative scenarios

The modelling shows that if the UK had done nothing to try to prevent the spread of Covid-19, as much as 81 per cent of the population would have become infected and up to 550,000 people would have died, with the peak coming after three months.

“Mitigation” measures like asking people over 70 and with underlying illnesses to distance themselves from others would cut deaths by half but leave excess mortality in the region of 260,000, according to the study.