Vallance and Whitty hit back over ‘scary’ lockdown graph criticism

Sir Patrick Vallance and Professor Chris Whitty have come under fire over slides used during the weekend announcement of the second Covid-19 lockdown. Today, the pair hit back. 

A chart suggesting there could be up to 4,000 deaths per day by December under a reasonable worst-case scenario was described by Oxford expert Carl Heneghan as 'now proven to be incorrect'. The modelling on which the chart was based appeared to be out of date, indicating that daily deaths would have already hit 1,000 a day. In fact, in the most recent stats yesterday, the UK saw 136 coronavirus deaths.

Despite this, Vallance insisted the purpose of the graphic was 'not to frighten people'. While Whitty, the Chief Medical Officer, told MPs at the House of Commons Health Select Committee that the projection is 'not intended to happen':

'There is a danger with these extreme forward projections that people misinterpret them as 'this is going to happen' and...get unduly worried about something that is not intended to happen. The whole point of a reasonable worst case scenario is to say, 'Right, we're going to do something to stop this happening.'

Chief scientific adviser Sir Patrick Vallance also defended himself against criticism over the graph. He compared it to the backlash which greeted the pair's press conference on 21 September, when they said Britain could see 50,000 new coronavirus cases a day by mid-October – and 200-plus deaths per day by November – without action. 

While the latest Department of Health figures showed 18,950 people tested positive for the disease – a drop on the day before – last Friday's figures revealed that 274 Covid fatalities were recorded, suggesting that the prediction was, if anything, optimistic. 

Asked by MPs whether the purpose of the latest graph was to 'frighten people', Vallance said:

'We went through this a bit on the 20th September, when we said we thought we could be heading to 50,000 cases a day if we had a doubling...and that deaths might reach 200...It was there to give a scenario. As it happened, the numbers turned out to be pretty close by the time we got there, so it's very difficult to project forwards in a way that doesn't inevitably lead to a problem of 'Is that real?'

'No, it's not real, it's a model. But it is what we need to understand, because this is a disease which is spreading, like all epidemics, in a way that will affect us in weeks to come, but isn't felt today. And i think there is that balance between trying to explain what may be coming, basing things, as Chris has said, as far as possible on what data you have today...but giving illustrations of what may happen in the future...because the tendency is otherwise to wait and find out in a few weeks' time, by which time you have baked in three or four weeks of cases.'

While Vallance and Whitty's defence of the graphs makes sense, it seems that this was a row that Downing Street could have easily avoided. When Saturday’s doomsday graph was shown to viewers, the source of the 4,000 deaths a day claim (which has subsequently been revealed to be a Cambridge/Public Health England (PHE) estimate) was not revealed. Given the gravity of what Boris was announcing in telling Brits to stay at home for four weeks, it is baffling that the Prime Minister was not more transparent with what the stats were saying in the first place.