The second Covid crisis

As the second wave of Covid intensifies and with the WHO about to send a team to China to examine the origins of Covid-19, it is interesting to reflect on where we stand in the current cycle and what we know from past pandemics. To date, more than 1.9 million people worldwide are estimated to have died during the current pandemic which has now entered its second year (the first death in China was recorded on 11 January 2020). This compares with the inappropriately named Spanish Flu epidemic of 1918-19 which is estimated to have claimed more than 50 million lives. 

Comparisons with the Spanish Flu 

Evidence based on records back to the sixteenth century suggests that the influenza virus mutates relatively slowly with a dominant strain emerging only every 2-3 years. Since each variant tends to adapt to prevailing climatic conditions, seasonal weather patterns and the associated change in human behaviour reduce its ability to thrive thus limiting its spread and the potential for rapid mutation. This was not the case in 1918-19 when there were three waves of the disease within a relatively short period (chart 1). In the words of Jeffery Taubenberger and David Morens in this excellent paper, “Acquiring viral drift sufficient to produce new influenza strains capable of escaping population immunity is believed to take years of global circulation, not weeks of local circulation. And having occurred, such mutated viruses normally take months to spread around the world.” Even now it is not clear that virus mutation was responsible for the spread of the disease but it remains the most plausible explanation.

Just as was the case a century ago, a second wave has emerged very quickly and it is almost certainly the result of virus mutation. Developments in genome sequencing mean that we can now identify new strains more quickly. The variant of Covid-19 that spread across the world last spring (D614G) was already different from the initial SARS-CoV-2 strain identified in China, and new strains have since been identified in the UK, South Africa and Japan. The UK variant is known to be more infectious than previous strains of the virus, raising the R (reproductive) number in Britain by between 0.4 and 0.7 with latest estimates putting the R value between 1.0 and 1.4 (infections will only tail off if the R number is below one). For the record, at its peak the Spanish Flu virus was estimated to have an R number between 2 and 3.

Getting worse before it gets better

It now appears that countries which escaped relatively lightly during the first wave of the pandemic are being more heavily affected this time around. At the start of November, Germany and Switzerland reported mortality rates of 13 and 27 respectively per 100,000 of population. Latest statistics suggest the German mortality rate has almost quadrupled to 49 whilst the Swiss figure has risen to 94. Mortality rates in the US and UK, which were running at 70 per 100,000 in early November, have risen to 114 and 122 respectively whilst Italy is running at 130 and Belgium has spiked up to 175 (chart 2). There will be a time to discuss what different countries did right and what they did wrong which has led to such differing incidences of the disease. But that time is not now: We can leave the recriminations until later as governments put their efforts into bringing the spread of Covid-19 under control.

Lockdowns: Harder or smarter?

There are high hopes that the vaccines which are now being rolled out will help limit the spread of the disease, reducing the strain on the health system and ultimately mortality rates. But these will take time to work through the population and we must thus continue to rely on lockdown measures. Lockdowns remain highly controversial almost ten months after they were introduced across Europe and not surprisingly the longer they last, the more people begin to get fed up. Psychologists argue that they can only work on a sustainable basis when there is a partnership between governments and the people. There must be no “them and us.” It is thus vital to get the tone of the message right when asking society to make significant sacrifices.

The approach by the UK Home Secretary, Priti Patel, who noted in yesterday’s daily briefing that a minority of people are “putting the health of the nation at risk by not following the rules … If you do not play your part, our selfless police officers... will enforce the regulations and I will back them to do so” is precisely the wrong way to go about ensuring compliance. The psychologist Stephen Reicher, who is part of the government’s Scientific Advisory Group for Emergencies (SAGE), argues that blaming the public for non-compliance undermines trust and threatens the success of the measures He noted in a Tweet that, “Patel is disastrously wrong in nearly every way: Lack of public compliance is NOT the problem: by and large people ARE complying.” He further noted that “the real problem is not that people are 'flexing’ the rules but that the rules are too flexible … And harsh enforcement only makes a dire policy still worse … Certainly use enforcement as a last resort, but engaging explaining and encouraging the public works far better.”

Harsh enforcement measures serve to stir up public anger and give oxygen to the anti-lockdown campaigners, who argue that Covid tends to be of greatest harm to the elderly and those with pre-existing health conditions and that the disease is little more deadly than normal seasonal flu (even now, this kind of false message is being peddled on websites such as lockdownsceptics.org). The fact that this view is widely held has forced the media to confront the issue. But as this BBC interview from last week demonstrates, the debate continues to be held in an echo chamber. Since neither the pro- nor anti-lockdown protagonist have a background in epidemiology, most people were left with the impression that the interview was designed merely to stoke up debate rather than shed any light. Moreover, the below-the-line comments on YouTube were overwhelmingly in favour of the anti-lockdown proponent. The government’s message is clearly not getting through.

Whilst there is a growing body of empirical work to support the notion that lockdowns work, they do impose a large economic cost. This raises the question whether it is possible to impose lockdowns whilst minimising the degree of disruption. A paper by Chen et al in the CEPR’s large and expanding collection of Covid economic research (here), which suggested that the type of lockdown matters, thus caught my eye. Their empirical analysis across 75 countries which tracks changes in the R value against the Oxford COVID-19 Government Measure Tracker (OxCGRT) and the Google mobility indices concludes that “gathering bans appear to be more effective than workplace and school closures.” They also offered empirical support for the belief that larger household sizes tend to diminish the effectiveness of mobility reductions which mitigates against the effectiveness of such measures in developing countries.

This is an important insight ahead of suggestions that the UK government may be considering an even stricter lockdown. However, the evidence suggests that the rate of infections may be slowing down – the number of positive tests on 11 January was more than 20% below the levels a week earlier. We may be able to get away without any appreciable tightening of the restrictions. Indeed, based on the OxCGRT data Germany, the Netherlands and Sweden are amongst the few countries to have a stricter lockdown in place today than in the spring of last year and the strictness of the European average lockdown index is somewhat lower than at its 2020 peak (chart 3).

Even if lockdowns are not tightened, they are almost certainly not going to be eased anytime soon. The German government has suggested that lockdown measures could remain in place for another 8 or 10 weeks whilst the Dutch national lockdown has been extended by three weeks to the end of the first week of February. As a result the pain experienced by the services industries, which are most heavily impacted by social distancing rules, will continue into the early months of 2021. It is increasingly looking as though the early part of the year will register significant output contractions across Europe as the hoped-for economic recovery remains elusive.