Oliver Johnson

Yesterday saw the latest performance of one of the longest-running dramas in town. In many ways, the Covid inquiry felt very much like a slightly unnecessary reboot (Matrix Resurrections style) of Cummings’s appearance at the Parliamentary Science and Technology Committee back in May 2021. We didn’t learn a lot yesterday that we didn’t know then, for all that the political correspondents tried to breathlessly repackage ‘revelations’ about Boris Johnson not understanding life expectancy that we’d known about since July 2021.  But to me, Cummings’s appearance was actually a remake of an even earlier drama. The 2019 Channel 4 programme Brexit: The Uncivil War was bookended by exactly this scene.

The official Covid-19 dashboard has turned green and cases appear to have peaked, at least for now. You hear a lot of people say 'cases don't matter', but they are a leading indicator of hospitalisations and deaths — and so a peak in cases (if confirmed by the ONS survey) should lead to a peak in hospitalisations in future weeks. So, is that it? Are we done? It would be unwise to estimate the R numbers for a few days. Not because I'm disappointed that numbers are falling, but because you can't do linear regression on non-linear data. And there is still a lot of uncertainty. However, for the first time in 18 months, there's been a fall in cases that can't be easily explained by a national lockdown. That's great news.

Few topics during the Covid pandemic have caused more controversy than the Herd Immunity Threshold, the level of immunity at which the virus can no longer spread through a population even once social distancing is relaxed. Confident past predictions that Sweden or India had reached this have been swept away by sizeable second waves, and certainly we cannot tell from graphs of falling cases alone that herd immunity has been achieved. However, considering the latest data, I believe it is worth asking whether parts of the UK have passed the Herd Immunity Threshold. The answer may be 'not quite yet', but it can be useful to think why. Essentially, herd immunity should be possible given enough infections and vaccinations, conditions that may apply in parts of South Wales, for example.

The Pfizer vaccine’s approval by UK regulators marked what many hope is the beginning of the end of the coronavirus crisis. That was certainly the impression Boris Johnson was keen to convey during his Downing Street press conference on Wednesday. The Prime Minister, however, warned the British people to avoid being overly optimistic. Deputy chief medical officer professor Jonathan Van-Tam went even further: ‘I don’t think we’re going to eradicate coronavirus,’ he said, ‘I think it’s going to be with humankind forever.’ If professor Van-Tam is correct, what can we expect to happen in our battle against the virus in the coming weeks and months?

With Primark open, parents can once again buy cut-price school uniforms for their children. Whether those children will get to wear them before they grow out of them is an open question. The government has abandoned plans to get all primary school children back into the classroom before the end of term, and Matt Hancock has questioned whether secondary school children will even be back in September. But was it necessary to close schools at all? The Imperial College Report 9 of 16 March is credited with changing the government’s coronavirus policy and sending the country into lockdown. Yet the report did not really press for closing schools. Its data suggested that taking this action would only reduce total deaths by between 2 and 4 per cent.

Dominic Cummings placed a job advert back in January calling for data scientists, statisticians and modellers. Since then, the coronavirus epidemic has made all of us 'weirdos and misfits' in our growing obsession with data. Everyone now has opinions on the latest coronavirus statistics, whether it's South Korean test numbers, German fatality rates or Italian regional differences. The latest data visualisations get shared widely across the internet. But how should we make sense of them? To a professional mathematician like me who gives lectures about probability and uncertainty, the rise of the epidemic modellers is somewhat bewildering. Compared to the problems I normally work on, modelling the epidemic is both incredibly easy and unbelievably hard.