Pandemics are not only caused by viruses

Experts know that coronavirus disease (COVID-19) is of viral origin. But where did the disease-causing virus, SARS-CoV-2, originate? Two compelling theories permeate public discussion over this question at present. Either the initial outbreak involved viral transmission among animals that “spilled over” into human populations, or the novel coronavirus strain accidentally “leaked” out of a highlevel biosafety laboratory. In the (far more likely) spillover scenario, SARS-CoV-2 circulated in animals and trickled out of nature, an organic result of commonplace zoonotic interactivity. In the lab leak scenario, SARS-CoV-2 was developed in a research facility and escaped accidentally, possibly as a result of human error. Ultimately, these question-of-origin stories boil down to a seemingly crucial distinction: was the pandemic caused by nature or by humans?

The answer to this question holds high stakes – insofar as it will steer policy directions or possibly punitive measures, which could further politicize cosmopolitan science. If the Lancet and WHO investigative teams determine that the virus emerged naturally from somewhere along the human-animal-environment interface, then a deluge of funding to restrict wildlife trade, regulate the food industry, increase pathogen discovery in targeted hotspots, etc., would likely follow. Whereas if they were to conclude that the virus emerged from a lab, then new restrictions on life sciences research enforced, investments drained from certain types of gain-of-function research, and the rules governing international cooperation in science safety and global security might need to be renegotiated if not litigated. Any of these measures – and I have imagined only a few – would appear to be valid and reasonable responses aimed at reducing the risk of another pandemic going forward.

Yet there are risks, as well, implicit in the assumption that preventing the next pandemic hinges upon our ability to locate the origins of this one. Whether the virus emerged from a tourist-friendly cave, wet-market, or lab, we already have tools and rules for risk reduction in such places or else infrastructures in the process of being built and strengthened, albeit these are not always enforced. We also know that processes like climate change and habitat destruction create interfaces for viral evolution and that human-animal-environment interfaces are common sources of zoonotic transmission. Zoologists and epidemiologists understand that viruses are passed along “convoluted rivers of emergence”. In other words, when it comes to establishing causation, there will probably be leaks and spills all the way down.

In the case of COVID-19, it is quite possible that no discrete origin will be found, no singular human-animal encounter, no patient zero, no smoking gun. It is even possible that SARS-CoV-2 emerged in the admixture of more than one origin story in a dynamic web of causation. Multiple factors drove the viral pandemic into emergence. Most were out of human control, but several others directly involved human practices, including actions (and inactions) guided both by passions and by phobias. The failure to cooperate on viral surveillance without fear of political reprisals, economic sanctions, or prejudiced attributions of overreaction – at the local, regional, national, and transnational levels – are factors that directly delayed decisions to notify, tocoordinate, and to respond to the pandemic as it emerged. This is to say: how humans reacted to the threat of COVID-19 were as much a cause as any origin.

The pandemic was not caused by viruses alone. So then what difference does it make, beyond its effect on the likely practicalities of institutional response, whether SARS-CoV-2 issued from sources conceived as natural or man-made? Either way, preventing the next pandemic will require investing in preparedness, strengthening early detection, improving coordinated national response capacities, repairing international relations, and incentivizing – not penalizing – transparency with regards to information-sharing (especially when the news is not good). These are the causes we ought to pursue. For they might very well become the preferred origin story of another pandemic, one that we avoided in a future yet to come.

In the end, the question-of-origin stories boils down to another crucial distinction: diagnosing the etiological origins of COVID-19 and identifying the epidemiological drivers of SARS-CoV-2 emergence in human populations are not the same as determining what went wrong to cause the pandemic.

Melissa (Mel) Salm is a PhD candidate in the department of Anthropology at the University of California, Davis. She is currently completing her dissertation on One Health approaches to infectious disease epidemiology in Peru.