As we head into our fourth year with Covid 19, this is a reasonable question to pose. This is an interesting editorial from this week’s New England Journal of Medicine on the subject.
On April 10, 2023, U.S. President Joe Biden signed a resolution officially terminating the Covid-19 national emergency in the United States. The public health emergency ended 1 month later. In September 2022, Biden had stated that “the pandemic is over,” when during that month, there were more than 10,000 deaths involving Covid-19 nationwide. The United States is, of course, not the only country to have made such pronouncements. Several European countries declared an end to the emergency associated with the pandemic in 2022, lifting restrictions and starting to manage Covid-19 more like influenza. What insights can be derived from past declarations of this sort?
Three centuries ago, King Louis XV decreed the end of the plague epidemic that had been ravaging the south of France. The plague had caused a staggering number of deaths around the world over multiple centuries. From 1720 to 1722, more than half the population of Marseille died. The decree, whose main purpose was to authorize merchants to resume their commercial activities, invited people to hold bonfires in front of their houses in a “public rejoicing” at the cessation of the plague. Full of ritualized symbolism, the decree set the standard for the way in which the end of an epidemic would be declared and celebrated. It is also a stark reminder of the economic imperatives behind such declarations.
But did the decree end the plague? Of course not. At the end of the 19th century, there was a plague pandemic during which the causative agent, Yersinia pestis, was discovered by Alexandre Yersin in Hong Kong in 1894. And although some scientists assume that it disappeared in the 1940s, the plague is far from a historical relic. It persists as an endemic zoonotic disease that has been transmitted to humans in rural areas of the western United States and, more commonly, in Africa and Asia.
We might ask, then: Do pandemics ever end? And if so, when? The World Health Organization has considered an outbreak to be over when no confirmed or probable cases are reported for a period of twice the maximum incubation period of the virus. On the basis of this definition, Uganda declared the end of the most recent Ebola outbreak in the country on January 11, 2023. But since pandemics (a term derived from the Greek pan, meaning “all,” and demos, meaning “people”) are sociopolitical as well as epidemiologic events that unfold on the global stage, their end — like their beginning — is determined not only by epidemiologic criteria but also by social, political, economic, and ethical concerns. Given the challenges associated with eliminating pandemic viruses (including structural health disparities, global tensions affecting international cooperation, human mobility, antiviral resistance, and ecologic disruptions that can alter wildlife behavior), societies have often chosen a less socially, politically, and economically costly strategy. This approach involves accepting as inevitable some deaths among certain groups of people who are socioeconomically disadvantaged or have underlying health conditions. Pandemics therefore end when societies adopt a pragmatic view of the sociopolitical and economic costs of public health measures — in short, when they normalize the associated mortality and morbidity. In doing so, they also contribute to what might be called the “endemicization” of diseases (“endemic” is derived from the Greek en, meaning “in,” and demos) — a process that involves tolerating a certain number of infections. Endemic diseases typically cause occasional community-level outbreaks without saturating emergency departments.
Influenza can serve as an example. The 1918 H1N1 influenza pandemic, commonly referred to as the “Spanish flu,” caused 50 million to 100 million deaths worldwide, including an estimated 675,000 deaths in the United States. But the H1N1 strain didn’t disappear and continues to circulate in the form of milder variants.1 The Centers for Disease Control and Prevention estimates that an average of 35,000 people in the United States have died from influenza each year over the past decade. Societies have not only “endemicized” the disease, which is now seasonal, but have normalized the mortality and morbidity it causes year to year. They have also routinized it, in the sense that a general understanding of the number of deaths that societies can tolerate or manage has been incorporated into social, cultural, and health behaviors, and expectations, costs, and institutional infrastructures.
Another example is tuberculosis. Although one of the health targets of the United Nations Sustainable Development Goals is to “End TB” by 2030, it remains to be seen how this goal can be accomplished if absolute poverty and staggering inequality continue to exist. The so-called silent killer is endemic in many low- and middle-income countries, where lack of essential medications, inadequate health care, malnutrition, and crowded housing conditions allow it to thrive. Tuberculosis mortality increased for the first time in more than a decade during the Covid-19 pandemic.
Cholera has also been endemicized. In 1851, cholera’s health effects and detrimental consequences for international trade prompted representatives of the various imperial forces to convene in Paris at the first International Sanitary Conference to discuss ways to contain the disease; there, they developed the first global sanitary regulations.2 But the health threat from cholera never really ended, despite the discovery of the causative pathogen and the disease’s relatively straightforward therapeutic management (consisting of rehydration and antibiotics). Each year, there are 1.3 million to 4 million cases of cholera and 21,000 to 143,000 associated deaths worldwide. In 2017, the Global Task Force on Cholera Control developed a roadmap for ending cholera by 2030. Yet recent years have seen an upsurge in cholera outbreaks in conflict-ridden or impoverished areas throughout the world.
Perhaps the most appropriate example of a recent plague is that of HIV/AIDS. In 2013 at the Special Summit of the African Union in Abuja, Nigeria, member states committed to taking steps toward eliminating HIV and AIDS, malaria, and tuberculosis by 2030. In 2019, the U.S. Department of Health and Human Services similarly announced an initiative to end the HIV epidemic in the United States by 2030. There are about 35,000 new HIV infections in the United States each year, in large part because of structural inequities in diagnosis, treatment, and prevention,3 and in 2022, there were 630,000 HIV-related deaths worldwide. Yet although HIV/AIDS remains a global public health issue, it is no longer considered a public health crisis. Instead, endemicization and routinization of HIV/AIDS and the success of antiretroviral therapy have turned it into a chronic disease that is now competing for resources with other global health problems. The sense of crisis, priority, and urgency that was associated with HIV when the virus was first discovered in 1983 has been dampened.4 This social and political process has normalized the deaths of thousands of people each year.
The declaration of the end of a pandemic therefore marks a critical point when the value of a human life becomes a variable of actuarial significance — in other words, when a government determines that the social, economic, and political costs of saving a life exceed the benefits of doing so.5 It is worth noting that the endemicization of diseases can be associated with economic opportunities. There are long-term market considerations and potential financial profits related to the prevention, treatment, and management of once-pandemic diseases. The global market for HIV drugs, for example, was valued at about $30 billion in 2021 and is projected to reach a value of more than $45 billion by 2028. In the case of the Covid-19 pandemic, long Covid, which is now seen as an economic burden, might turn out to be the next pharmaceutical boon.
These historical precedents make clear that it is neither epidemiology nor any political declaration that determines the end of a pandemic, but the normalization of mortality and morbidity by means of a disease’s routinization and endemicization — what in the context of the Covid-19 pandemic has been called “living with the virus.” What ends a pandemic, too, is governments’ conclusion that the associated public health crisis is no longer a threat to the economic productivity of a society or to the global economy. Ending the Covid-19 emergency therefore amounts to a complex process of adjudicating powerful political, economic, ethical, and cultural forces — it is neither the result of an accurate assessment of the epidemiologic reality nor merely a symbolic gesture.
Disclosure forms provided by the authors are available at NEJM.org.
This article was published on October 7, 2023, at NEJM.org.