Has Neil Ferguson been proved right about Covid?

Calculated risk

It is a year since Neil Ferguson’s Imperial College team published the paper that inspired the government to call the first lockdown. How good were its scenarios?

— It modelled four Covid-suppression measures: isolating cases for seven days, their household contacts for 14 days, social distancing to reduce household contacts by 75 per cent and the closure of schools and hospitals. It assumed these measures would be repeated for 12-18 months before a vaccine became available.

— The model was run with different values for the basic reproduction number, which it estimated to lie within the range 2 to 2.6. If the government introduced none of these measures it estimated there would be between 410,000 and 550,000 deaths.

— If all four were enacted, it estimated between 5,600 and 48,000 deaths, depending on the R number and the level of ICU admissions at which the government enacted the repeated lockdowns.