Why Didn’t The UK Lockdown Sooner And Prevent Thousands Of Deaths?

Whether the delay was due to a failure in modelling, communication or policy remains to be seen, but is a vital question to answer, professor Kit Yates writes.
Britain's Prime Minister Boris Johnson leaves Downing Street
Britain's Prime Minister Boris Johnson leaves Downing Street
ASSOCIATED PRESS

The UK has the worst Covid-19 death toll in Europe. This is despite the fact that the country had ample warning of what was to come. On 12 March, Chief Scientific Officer Sir Patrick Vallance declared that we were four weeks behind Italy in terms of the scale of the epidemic. At that point, Italy had already recorded 1,000 deaths and 15,000 cases. As it turned out, the “four weeks” claim was never correct – the UK reached the grim milestone of its first 1,000 reported deaths just 16 days later. Nevertheless, despite having around a two-week head start, the UK has still emerged from the first peak of its epidemic in a worse state than almost any other country in the world.

It’s important to treat comparisons between countries with care. Not all countries are reporting deaths in the same way and countries can move a few positions in the league table when different statistics are considered. However, almost any angle from which you chose to shine the light – case fatality rate, absolute recorded deaths, crude mortality or excess mortality – casts an unflattering shadow on the UK’s performance.

Although fine-grained comparisons near the extremes of these morbid league tables might be difficult, comparisons with countries like Germany bring the full extent of the UK’s failings into sharp relief. Germany, with a total population of over 83 million, and despite locking down on the same day as the UK, has recorded fewer than 10,000 deaths. In early March, The World Health Organisation advised governments around the world to do everything in their power to supress the spread of the virus. Germany rolled out a widespread test-trace-isolate programme. Contrastingly, on the 12th of March, the UK government abandoned community testing and contact tracing. Throughout the period before lockdown Germany consistently tested more people in a typical day than the UK did in a whole week. Arguably, the UK did not have the capacity to scale up it’s testing to German levels, but could the UK have mitigated the scale of the disaster by locking down sooner?

The mathematical modelling community has been remarkably quiet on this issue. However, a few people have started to ask could, and should, the UK have done better? Modelling carried out by the British scientist James Annan suggests that locking down even a week earlier might have cut the UK’s death toll down to a quarter of its current size, saving tens of thousands of lives.

His underlying modelling is relatively complex (although a dramatic simplification compared to the much-talked-about “Imperial College” model of Neil Ferguson’s group), but the basic premise can be summarised easily enough. In the week before the UK enforced the lockdown, cases were growing exponentially, doubling roughly once every three-and-a-half days. This means that, over the course of a week (two doubling periods), cases would have increased four-fold. Locking-down a week earlier translates to beginning lockdown with roughly a quarter of the total cases and maintaining this factor throughout as cases drop-off exponentially. A quarter of the expected cases should translate to a quarter of the expected deaths, or fewer, given that the NHS would not have been nearly so stretched.

Not only would locking down earlier have saved thousands of lives, but it would also have decreased the time for case numbers to reach manageable levels, putting the UK in a better position to begin to re-open its economy sooner, whilst still buying time to increase NHS capacity and scale up testing.

These findings might be accompanied by the caveat that the lockdown may not have been taken so seriously, and consequently may not have been so effective, had people not seen the impact a more developed outbreak would have. However, evidence from other countries, like Australia and New Zealand, suggest that the catastrophe does not have to be unfolding on their own doorstep in order for a population to be compliant with lockdown.

It’s easy to highlight the failure to lockdown early and its consequences in hindsight. No-one would argue that decision-making under the pressure of an emerging pandemic is fraught with difficulty. Nevertheless, in the early stages of the UK’s epidemic, when the case numbers were growing exponentially, it would not have been difficult predict that earlier suppression would have had dramatic and beneficial consequences for the number of cases and deaths a short time down the line. Whether the delay in the decision to lockdown was due to a failure in modelling, communication or policy remains to be seen, but is surely a vital question to answer if we are to learn from the mistakes the UK has made.

Kit Yates is senior lecturer in mathematical biology at the University of Bath.