COVID-19 started in an animal host; new policy could help prevent the next outbreak

Tomasz Walenta

Laura Kahn *02
Courtesy Laura Kahn
Laura Kahn *02, a physician and research scholar at Princeton’s Woodrow Wilson School, studies the politics of infectious disease, including how leaders can make better decisions during outbreaks and how global-health policy can better prevent and mitigate zoonotic diseases, which are transmitted from animals to humans. These diseases include SARS, Ebola, and now COVID-19. PAW interviewed Kahn about how governments should respond to such pandemics and how the world can stop them from happening again. 

What are the most important things for decision-makers to know about the SARS-CoV-2 virus, which causes COVID-19? 

First, its origin: The virus is a betacoronavirus, a similar genus to SARS [Severe Acute Respiratory Syndrome] and MERS [Middle East Respiratory Syndrome], and one that’s very common in animals. There are several theories as to the host of this disease, but what’s more important is the root cause of why zoonotic diseases emerge. In all cases — SARS, MERS, and now SARS-CoV-2, also Ebola, and variant Creutzfeldt-Jakob Disease — they emerge directly or indirectly because of humanity’s demand for animal protein, specifically in the form of meat. 

Second, its case-fatality rate: MERS and SARS had higher fatality rates — about 34 percent and 10 percent — than COVID-19, which currently ranges between .25 percent and 3 percent. It could be even lower, since that number doesn’t include the many asymptomatic cases. 

Finally, its spread: Because people, especially healthy children and young adults generally have milder symptoms, they might be more likely to spread the disease to those who are more vulnerable. 

How do viruses like SARS-CoV-2 jump from animals to humans? 

Our most intimate way of interacting with our environment is eating it — through animal protein, dairy, eggs, or even eating plants, you’re always going to risk consuming microbes that might make you sick. We have known for a long time that there are many viruses lurking in the environment, particularly in wild animals. In the case of SARS and COVID-19, these viruses originate in horseshoe bats, and are then spread to humans via other animals. Capturing animals, destroying their habitats, selling them in large, live animal markets, and eating them is a time bomb for more diseases like these to emerge into human populations. 

To move from one host species into another, the virus’s surface proteins must be able to recognize and bind to the receptors on the host’s cells. Once the virus enters the cell, it can hijack the cell’s machinery to make new viruses. The SARS-CoV-2 virus uses a human receptor called angiotensin-converting enzyme 2 (ACE2). It is the same receptor that antihypertensive drugs called ACE inhibitors use. So people taking ACE inhibitors have been advised to talk to their doctors about whether or not they should continue taking them. MERS uses a different receptor. 

What could have been done to prevent a zoonotic pandemic like this from starting in the first place?

My book One Health and the Politics of Antimicrobial Resistance, and the One Health concept that I develop there and elsewhere, shows how human and animal and environmental health are linked. This link may seem obvious, and it has been recognized by indigenous peoples around the world, but in practice, our institutions are strongly speciesist. This is to say, they only care about humans without thinking about other animals. When we do that, we miss a huge part of our world. 

In this country, for example, there’s no CDC for animals: The USDA cares about food animals, the CDC studies rabies, and the Department of the Interior does some surveillance of fish and wildlife. We need coordinated surveillance of wildlife, domesticated animals, and people to monitor the emergence and spread of diseases. Ideally, we should have a department of animal and environmental health that monitors the health of all animals (companion, livestock, and wildlife) because their microbes impact our microbes. And we need more funding for research on animal health and disease. 

In questions of human medicine, vets are generally ignored, even though they have important expertise in many of the problems we face today, from climate change to zoonotic diseases. We need to recognize that animal health is important for our own health and well-being. If we just focus on humans and make assumptions, then we’re not going to make any effective policy. 

You’ve studied how political leaders handle pandemics. How are U.S. leaders handling this one?

Writing my book Who’s in Charge, about leadership during public-health crises, I found that whether a political leader like the president or an expert appointee  like Dr. Fauci was the face of the government’s response to the crisis, it was important for both leaders to act in concert, and for the political leaders to listen to the experts. 

At the beginning of this crisis, the U.S. federal government made every mistake you can make. By playing down the severity of the pandemic in early press conferences, President Trump created large swaths of the population who thought it was not as serious as it was. In fact, the CDC’s tests were faulty to begin with and slow to roll out, so we have to assume that there are actually many more cases in this country than we know about. And by acting like closing borders would prevent the crisis and calling the virus a “Chinese virus” or “foreign disease,” our leaders created scapegoats, which stigmatizes the disease and makes testing and treatment — and public-health responses like social distancing — even harder. 

This president also gutted the CDC; he removed the best experts and the infrastructure that we need to have ready. People forget that these bureaucrats are extremely important in our safety and well-being. 

Will social distancing as practiced currently be enough to slow the outbreak? 

It’s hard to predict the future. I’m optimistic about finding an effective drug to treat the infection. However, because the U.S. has been so slow to initiate widespread testing, we will have many more cases than if we had implemented stringent airport screenings, testing, and quarantine. This was a monumental failure of the Trump administration. In the short term, it’s going to get worse before it gets better. Largely, state and local governments have had to step up to the plate and develop their own policies without federal guidance or assistance.

The Constitution places the responsibility of public health on the shoulders of state leaders, and that means the governors are legally in charge during public-health crises. Local governments implement the responses. When the Constitution was written, it was 75 years before the germ theory of disease, and modern medicine didn’t exist. The founders had no notion of microbes. Now we know that microbes don’t recognize political borders, which is why the national response is so important. But in some ways, we may be better off having public-health leadership as a state and local responsibility with this current crisis. 

What can individuals do to keep the pandemic from spreading in their communities?

The people who are most at risk are those who are older or with chronic illnesses, and we want these people to be protected as much as possible, which is why everybody should be sheltered in place. We don’t want to wait until the hospitals are completely overrun — we want to break the chain of transmission as soon as possible. It’s critical to curtail everything: Cancel trips, don’t go out, just basically hunker down and break the chain of transmission. 

What can we learn from this pandemic about what we owe one another?

For the remainder of this crisis, we need to pull together as a community, to remove all stigma of who you are or who you voted for, your race, your religion. This is a national crisis, and a global crisis, so we need to protect one another. 

Finally, we need to learn from this pandemic to address the other ongoing crisis, which is climate change. Society is not going to end because of this virus, but climate change has the potential to do that, and we need to be addressing this as such. We need to turn the same sense of urgency we have now in dealing with this pandemic to the ultimate goal of leaving a habitable planet for our kids and for future generations.

Interview conducted and condensed by Bennett McIntosh ’16.

This is a revised version of an interview posted on March 25, 2020.