More than two years after the World Health Organization declared the Covid-19 outbreak a pandemic and more than 18 months after Covid-19 vaccinations were first widely administered, it can still seem there is little consensus on what stage of the epidemic we are now at. Is the epidemic over, with British restrictions lifted a year ago and airline travel surging? Or do soaring case rates and continued individual health measures suggest the epidemic is nowhere near its end?
The trouble is that epidemics do not have the sort of neat, objective endings we may imagine. A swift and decisive endpoint, achieved through the speedy application of scientific innovation – a magic bullet treatment – is usually wishful thinking. It is unlikely we will see anything like that with Covid-19.
Analysing past epidemics shows us that actual endings are long, drawn-out and contested. Societies must grapple not just with the medical realities of the disease, harms and treatments, but the political and economic fallout from emergency measures, and disputes over who has the authority to declare an end and what should be measured to guide this process. This is why there is so much uncertainty about the current state of Covid-19: different groups have vastly different experiences of the medical, political and social aspects of the epidemic, and different ideas of what an ending may look like.
Research demonstrates that the end of an epidemic involves more than disease rates (the medical end). Instead, the end also encompasses the end of the crisis and regulations (the political end), and the return to normalcy (the social end). These endings are related, but they are different – and they can be at odds with one another. Analysing a variety of past epidemics reveals that it is more accurate to identify multiple endings to an epidemic, taking these different sorts of endpoints into account.
The history of recent epidemics such as H1N1 (swine flu) or HIV/Aids bears this out. Most epidemics end not with the disappearance of disease, but when case rates no longer result in a medical crisis – a point in which rates reach what is defined as normal, expected, or locally acceptable levels. In August 2010, for example, the WHO declared that the 2009 H1N1 pandemic was in its “post-pandemic period”. This did not mark the end of H1N1 cases; instead, the WHO explained that cases and outbreaks were still expected to occur, but following normal seasonal patterns of influenza. This raises the question of what is a normal, acceptable or manageable level in a given place – particularly for a new disease. Differences of opinion over responses to Covid-19 disease rates – whether to maintain or reinstate public health measures, and when to relax them – demonstrate debates as to what is an acceptable level of infection, as well as who should decide this.
As a result, the end process is when different forms of authority negotiate and compete with one another, often debating fundamental social, economic and political priorities as much as medical data. Even in the face of persistent circulation of a disease (whether H1N1 or Covid-19), events such as war and political instability can redirect public alarm and political resources to other crises, changing what local authorities and local communities deem “normal, expected, or locally acceptable” levels of disease. Concerns about the war in Ukraine or soaring energy prices pushed Covid-19 reporting to the background, regardless of case rates.
For example, while the HIV/Aids pandemic has faded from public attention, cases have not disappeared. Instead, medical treatment has transformed the disease from a highly publicised killer into a manageable, chronic condition. Yet access to such treatment varies, often remaining out of reach for many in the so-called global south. In fact, the success of medical interventions has ended the HIV/Aids epidemic in the global north, in many ways pushing its global end further out of sight and thus out of reach.
Political and social contexts fundamentally shape the pandemic’s medical end. In places such as Kenya, Covid-19 interacts with continuing outbreaks of HIV/Aids, Ebola, cholera and tuberculosis. Understanding the end of epidemics as a drawn-out process, in which disease continues on even after our attention fades, explains long-term and global patterns of epidemics.
While we are drawn to tales of quick and effective solutions to end outbreaks, such as John Snow’s removal of the Broad Street pump handle to end London’s 1854 cholera outbreak, such stories are often fables – not only did Snow never remove the handle, but cholera was declining at the time for other reasons. The true account of cholera’s end in London was gradual, requiring political negotiation over how to implement improved urban infrastructure and sanitation alongside slow social improvements – rather than the incisive insight and decisive action of one individual. And, as with HIV/Aids, regardless of modern epidemiological knowledge, cholera outbreaks continue to this day – tied to political and social crises.
Epidemics are not a series of discrete biological events that simply pass into history with the disappearance of the disease. They are also moral crises, testing the limits of social cohesion and trust. As we are seeing now for Covid-19, the end process is a period of moral reckoning, with discussions of “lessons learned” and the crafting of narratives featuring heroes and villains. We seem to be in the midst of such a process, as medical experts debate what are acceptable infection rates, politicians debate the implications of lifting restrictions, and we debate with our relatives, friends and neighbours how best to live our lives.
Erica Charters is professor of the global history of medicine at the University of Oxford, where she leads a multidisciplinary project on How Epidemics End