Mrs Benn

There are those who like to doubt there is anything to be afraid of: climate change is a Chinese hoax; and Covid-19 is “little worse than the flu”. Such perspectives always lead to a call for inaction; the virtuous thing is to stand back and watch in amazement as well-intended fools rush round campaigning for “action”. The President of the United States began by dismissing Covid-19 as a hoax, then as a Chinese disease, before moving to reassuring promises that it would all blow over soon. Now the United States has about a quarter of global cases, and there is no evidence of any immediate relief from suffering. Our TV screens show emergency rooms overwhelmed by large numbers of critically sick patients, and doctors struggling to cope. Reality has intervened and asserted itself. For Covid-19, Reality’s decisive interventions have come comparatively quickly – within a few short weeks of the predictions of global pandemic. With climate change, it may be years before we reach the point at which even the staunchest doubters have no option but to come to terms with Reality – but by then there is a risk that we will have begun an irreversible slide towards a much greater catastrophe.

At least in relation to climate change, there is a global scientific consensus on the broad nature of the problem and the mitigation strategy that is required. The Covid-19 pandemic has exploded globally without clear consensus about the best way to mitigate its consequences. The World Health Organisation (WHO) is firmly of the view that the solution is to “test, test, test”: identification and isolation of infected individuals holds the key to slowing the spread of Covid-19. A study in a small Italian town, where the entire population was tested, found that tracing and isolating infected individuals – including those who were asymptomatic – enabled the infection to be controlled.

But small towns are poor models for nations of tens or hundreds of millions. Controlling and  monitoring who enters and leaves a small town is feasible, but achieving the same control for a city of 100,000 or a million inhabitants, with a multitude of routes leading in and out, is a challenge that is immensely more difficult.

Moreover, Covid-19 is a new disease. Yes, coronavidae is a class of many related virions, but Covid-19 presents a very important new challenge: infected individuals may be asymptomatic for as long as two weeks, and, indeed, may never develop symptoms. In ebola, infection leads rapidly to the onset of a severe illness and often to death; in contrast, Covid-19 leads to mild symptoms in the majority of cases, and no symptoms at all. In contrast to the WHO, many scientists are arguing that the genie is out of the bottle: Covid-19 infection is probably endemic and in dramatic contrast to ebola, its spread cannot any longer be prevented. The question is about how best to control the spread so that health systems are not overloaded.

In the UK a debate rages between on the one hand, the public health community, who favour the WHO’s approach; and on the other hand, epidemiologists who use powerful mathematical modelling tools to predict the development of infection. I have no specialist expertise, although the nub of the problem here is surprisingly close to many in my own academic discipline: the rate of growth of infected people will be the product of the rate of contact between people and the probability that contact leads to viral transfer. Biologists are only beginning to assemble the tools required to furnish a proper understanding of these fundamental parameters.

The final challenge in all of this is to understand the interface between epidemiology and public policy. There is a global shortage of Covid-19 test kits; there is no government on the planet that can test everybody who is suspected of infection and their immediate contacts. Moreover, the best test available, based on the detection of nucleic acids specific to Covid-19, only detects about two thirds of infections at the height of infection. There are no data on the efficacy of testing in the pre-symptomatic stage. On top of this, many tests being sold have been “falsified” by the WHO. And then there is the very difficult question of how Governments ensure the continued compliance with policy. For example, how dependent is the South Korean model, in which rigorous testing and contact tracing has apparently enabled the Government to control rates of infection and keep them low, while maintaining noral life, dependent upon a deeply-rooted national culture and a very specific relationship between the people and the Government?

We do not know the answers to these complex questions. For now Governments have to act. The illness is real, and real accident and emergency units are overloaded with real people who are suffering and dying, causing real grief. I do not envy politicians at this time. The UK Government is leaning on science for guidance, as it should, while scientists are struggling to achieve a consensus about the nature of the problems and the impact of the different solutions. Somehow Governments must lead us through these uncharted and stormy waters. These are difficult times. For my part all I can do is to follow as carefully as possible the Government’s guidance, and feel profoundly grateful for the selfless commitment to duty of hundreds of thousands of workers in the National Health Service.