History shows that most pandemics in the modern era last between 18 months and two years, and Covid-19 appears to be no exception.
Yet this timing is not caused by some strange microbiological mechanism: it reflects the amount of time needed for people and institutions to learn about the disease and develop ways to respond to it in a way that allows many to return to their normal lives.
Even though we can identify new pathogens and find treatments at lighting speed nowadays, once a disease has become a pandemic, it still takes that amount of time to recover from the disruption caused.
At the time of writing, early June 2021, it has been 18 months since the Covid-19 pandemic began; finally, there is some hope that many communities might return to living a new kind of normal within about six months, right on schedule.
No herd immunity for all
Of course, this hope for a return to normal life does not apply everywhere: those countries that do not have the resources to cope with Covid-19 may have to continue to live in pandemic conditions even after the pandemic is officially over.
Currently, some countries are still experiencing AIDS as a pandemic, while others do not. This is mostly because there are now effective treatments for AIDS, and there are public health systems in place to help manage the disease, at least for those who are lucky enough to live in regions where such resources are available.
Even though there is still no cure for AIDS, people with HIV living in wealthy countries can carry on more or less normal lives.
All the signs are that something similar is going to happen with Covid-19: it is unlikely that the SARS-CoV-2 virus that causes Covid-19 will ever be eradicated, and it is now increasingly unlikely that many countries will reach the famous ‘herd immunity’.
Yet for those living in wealthier and better resourced parts of the world, this will not radically affect our everyday lives once the pandemic is over.
For those living in less well-resourced parts of the world, the disease will probably become endemic, with sporadic outbreaks every so often.
Plague still remains endemic to some areas
This history highlights the way we live in an interconnected world that is also deeply unequal, and pandemics strongly highlight and even amplify those interconnections and inequalities.
There have been many different outbreaks of deadly disease across the centuries, including plague, smallpox, cholera, typhoid, yellow fever, leprosy, dengue fever, tuberculosis, malaria and, of course, several versions of influenza and coronavirus.
They are very different kinds of disease and most of them have little in common with one another, except for one thing: they have had devastating effects on human beings and social groups, often repeatedly.
Outbreaks of plague during medieval times devastated large parts of Europe and the Arab world, and some argue that these epidemics often changed the course of history. Nowadays there is almost no plague in Europe, but it still exists in other parts of the world, and occasionally, quite severe outbreaks still occur.
Many diseases that are now endemic to certain regions were introduced to those regions by colonisers, explorers and traders in previous centuries. Plague was introduced to several Latin American countries by Spanish colonizers, for example, and the disease still remains endemic to some areas of Latin America.
A social, political and economic phenomenon
A pandemic is officially defined as “an epidemic occurring worldwide, or over a very wide area, crossing international boundaries and usually affecting a large number of people”.
That definition points to the way that pandemics are both fundamentally social (pan-demic comes from Greek, meaning, “belonging to all of the people”), and that they involve interaction across borders: as people have travelled, often with animals and plants brought along with them, many millions of microbes have travelled with them.
Most of these microbes have been either harmless or even beneficial (we could not digest our food without them, for example). Sometimes, a few of these microbes have caused disease.
Yet whether that disease causes a pandemic, something that is devastating for people across the world, also depends on social, political and economic conditions that have little to do with the microbes.
The history of pandemics is a story about how people interact with each other and with the world around them: this pandemic will end when people are able to live normal lives while sharing the world with SARS-CoV-2; that ending may be a long time coming in some parts of the world.
Sarah Green is Professor of Social and Cultural Anthropology.