This past April, as Covid-19 deaths in the United States were climbing toward their terrifying first peak, a journalist with the conservative outlet Newsmax raised her hand during a White House press conference. Struggling to conceal a smirk, the reporter, Emerald Robinson, asked Donald Trump a question that seemed perfectly calibrated to feed the paranoid fever dreams of the far-right.

“US intelligence is saying this week that the coronavirus likely came from a level-four lab in Wuhan,” said Robinson, parroting a conspiracy theory with zero credibility. “There’s also another report that the NIH under the Obama administration in 2015 gave that lab $3.7 million in a grant. Why would the US give a grant like that to China?”

“I’ve been hearing about that,” Trump responded. “And we’ve instructed that if any grants are going to that area…we will end that grant very quickly.”

Quickly indeed. Just days after that savvy stagecraft, the National Institutes of Health (NIH) abruptly canceled a $3.7 million grant to the EcoHealth Alliance, or EHA, a New York–based scientific organization that conducts research around the world to identify novel pathogens and prevent deadly disease outbreaks.

For years, the EHA had been active in China studying coronaviruses in bats in the hopes of staving off the emergence of a SARS-like pathogen that could kill millions of people. Among the group’s partners in that federally funded work were scientists at the Wuhan Institute of Virology, which, since the emergence of Covid-19, has become a magnet for conspiracy theorists who have spread unfounded assertions that an accident at the lab caused the virus to spill into the human population. Trump’s embrace of this conspiratorial thinking appears to have intimidated NIH leadership into pulling the EHA’s funding.

In an April e-mail to the EHA informing it of the grant’s termination, a top official at the NIH offered only a vague justification for the decision, writing, “At this time, NIH does not believe that the current project outcomes align with the program goals and agency priorities.” With that, federal funding for the EHA’s work on coronaviruses in China came to a sudden halt.

“I think this whole thing has been a terrible mismanagement of science,” said Peter Daszak, a British zoologist and disease ecologist and the president of the EHA. “The director of the NIH has failed in his job miserably.”

The consequences, he said, have been significant for the organization and for him. He now receives daily threats from conspiracy theorists. He has been doxed and harassed and even received an envelope full of white powder at his home. Meanwhile, the EHA’s work with the Wuhan Institute of Virology and other partners in China has been brought to a standstill. After years of collecting samples in bat caves, identifying and analyzing new coronaviruses, and testing rural Chinese residents for antibodies, the group has been unable to access critical information that could help shed light on Covid-19 and other emerging coronavirus threats. The NIH, Daszak said, has effectively prohibited the EHA from continuing its collaborative coronavirus research in the country. “It is an outrage and extremely frustrating.”

“The US should be leading the world in getting ready for pandemics. We can do that, and that is what we were doing in China,” Daszak said. But “by instantly folding under pressure from the president, the NIH has reduced our ability to prevent the next pandemic coming out of China, and it has bolstered conspiracy theorists.”

Daszak is not alone in his distress. The termination of the EHA grant—which the NIH reauthorized in 2019—sparked a firestorm in the US scientific community. In May, 77 Nobel laureates signed an open letter to NIH director Dr. Francis Collins and Health and Human Services Secretary Alex Azar denouncing the grant’s cancellation, calling it “preposterous.”

“We believe that this action sets a dangerous precedent by interfering in the conduct of science and jeopardizes public trust in the process of awarding federal funds for research,” they wrote.

The outrage had an effect, if a modest one. The NIH technically reinstated the grant, but it imposed such severe restrictions and impossible demands on the EHA that the grant is still effectively suspended. The EHA has called the move “cynical.” The NIH, for its part, said in a statement that it “does not discuss internal grant deliberations” but confirmed that the grant remains “inactive pending resolution of grant compliance concerns.”

The consequences remain profound, Daszak said. By putting politics before science, as it so often does, the Trump administration jettisoned an important resource in this country’s effort to understand coronaviruses in China. Just as crucially, the White House undermined the principles at the heart of an even larger enterprise in which the EHA is a leading force.

That enterprise is known as One Health. Bringing together experts from across disciplines, One Health is an international movement that starts from the presumption that the fate of humans is intimately connected with those of wild animals and the ecosystems on which we all depend. Or, as a group of leading One Health advocates wrote in the Berlin Principles, a manifesto published in October: “We are starkly reminded of the basic fact: Human, animal, plant, and environmental health and well-being are intrinsically connected.”

The recognition of this reality makes One Health both a powerful antidote to the anti-science ethos of the Trump administration and a cutting-edge vision of 21st century global health. But advocates say it offers something else, too: It is one of our last, best hopes for preventing a pandemic even worse than Covid-19.

In the early 2000s, as Ebola outbreaks were flaring with increasing frequency across West Africa, Billy Karesh, a prominent veterinarian, gave an interview to The Washington Post to put the public health crisis in context. Ebola was making headlines because it had burned through the Republic of Congo and Gabon, where it killed scores of people in 2001 and 2002. But the disease was doing other damage, too; it was annihilating great apes in huge numbers, including gorillas, whose fragile populations couldn’t tolerate the terrible death toll. Karesh, a New Yorker who now works as a top scientist at the EHA, had spent years in Africa studying Ebola in apes. He knew how that virus behaves, spreads, and kills. He had studied its ecology. And when he spoke to the Post, he helped spark a movement.

The 2002 Ebola outbreak had reached the human population when one or more infected gorillas passed the disease to a hunter somewhere in the forest. This spillover and the resulting public health crisis were a wake-up call, he believed. Human and animal health are intimately intertwined, and Ebola was Exhibit A.

“Human or livestock or wildlife health can’t be discussed in isolation anymore,” he told the Post. “There is just one health. And the solutions require everyone working together on all the different levels.”

“One health”—it was a phrase Karesh uttered casually, but it has since become the name of an idea and a movement that aims to reshape the way human civilization approaches everything from public health to agriculture to wildlife conservation. As practiced by ecologists, veterinarians, medical professionals, and others, One Health begins with the recognition that most new diseases are zoonotic, meaning they pass into the human population from animals. Most often, these illnesses come from wild animals like apes, rodents, birds, or bats whose habitats have been degraded or that are being hunted, killed, or otherwise disrupted by human activity. A 2015 study by Karesh and his colleagues found that land-use changes like deforestation, urban sprawl, and road building are the leading drivers of pathogen spillover from wildlife to humans.

“When you are changing an ecosystem, when you are deforesting a landscape and converting it to monocultures, when you are bringing in livestock, building roads, building human settlements—all of these factors increase the risk of spillover,” said Catherine Machalaba, a policy adviser and research scientist at the EHA. “Together they dramatically increase the risk.”

These spillover events can have society-altering consequences. We are witnessing some of them now as the globe grapples with a deadly pandemic of animal origin that has killed more than a million people, infected 63 million, and thrown millions more out of work. And Covid-19 is hardly the first disease that has emerged from animal hosts and rewritten human history. AIDS, Ebola, SARS, Zika fever, and Lyme disease are just a sampling of recent plagues that have made their way into the human population from wild animals whose habitats we humans are gobbling up at a gluttonous pace. In fact, the emergence of zoonoses has been on the rise in recent decades. The Berlin Principles states it plainly: “The international spread of emerging infectious diseases…[has] created a world where regular outbreak and spillover events are the new norms.”

The One Health movement understands that environmental destruction has caused this lethal new normal. Its adherents believe the only way to safeguard human health is to protect animal and planetary health, too. No one is safe unless everything is safe. It’s a concept with deep roots in human history, most notably among Indigenous communities, and it contains many lessons for the future. One Health advocates say their transdisciplinary approach could not only stop the next pandemic but also assuage other threats like the rise of antibiotic-resistant bacteria and the burden of pollution-related illnesses. They say it even holds solutions to biodiversity collapse and climate disruption, two of the most dangerous crises facing humanity today.

But first, One Health has to overcome the obstacles that inevitably confront any attempt to recalibrate the balance between our species and the rest of the natural world. It has to confront the inertia of bureaucracies and the political and economic interests of the powerful.

We live in a world of microbes, most of which are shrouded in obscurity. Until recently, scientists didn’t even have a solid estimate of how many viruses this planet harbors. No one could put a number to the potential pathogens hidden in the far reaches of tropical forests, silently lingering in animal flesh, occasionally invading human bodies and causing havoc. 

That changed with Predict, a federally funded program that for 10 years sent scientists around the world searching for unknown viruses that might one day emerge from some bat, duck, or rat and kill people. Launched in 2009 in response to the H5N1 flu outbreak, the $200 million program was led by the US Agency for International Development (USAID) in partnership with the EHA, the University of California at Davis’s One Health Institute, and other groups that sought to establish a global network of virus hunters who could serve on the front lines of pandemic prevention. Predict accomplished a great deal during its too-short existence.

“When I designed the program in 2008 and launched it in 2009, it was really about opening up the aperture for viral discovery,” said Dennis Carroll, a biomedical researcher who led Predict at USAID and now leads the Global Virome Project. “We wanted to move viral discovery beyond humans into their primary reservoir—wildlife animals—in order to identify future viral threats.”

He said the program had three great accomplishments. First, its scientists were able to estimate how many unknown viruses are out there, circulating in wildlife. The number, according to Carroll, is 1.6 million—split among 25 families, from influenza viruses to coronaviruses to paramyxoviruses. Of that total, some 600,000 have the potential to spill into the human population, and a much smaller number still have the potential to cause illness in human hosts.

Predict’s work on this front, said Carroll, gave us “our first point of illumination” in the world “of viral dark matter.”

The program’s second accomplishment was simply establishing proof of concept: Could something like Predict work? The answer was yes. For 10 years, the program was able to send scientists to over 30 countries and develop research methods that collected nearly 150,000 samples from animals and identified roughly 1,200 new viruses. With a small army of local partners, it was able to train thousands of public health professionals and scientists around the world and lay the foundation for a global system of viral threat detection and prevention.

Finally, Predict was able to hone the scientific community’s understanding of spillover hot spots—biodiverse ecosystems like tropical forests where deforestation, agricultural expansion, settlement growth, and other disruptive forces are driving the emergence of novel infectious diseases by putting people and animals in close contact with each other.

The program, said Christine Kreuder Johnson, the associate director of the One Health Institute and a former Predict director, was an unprecedented initiative that “pioneered the One Health approach to pandemic preparedness and infectious disease surveillance.”

Scientists and researchers working under the auspices of Predict isolated and identified, among other discoveries, paramyxoviruses in Brazil, coronaviruses in China, an Ebola virus in Guinea, and a rhabdovirus that caused a deadly outbreak of acute hemorrhagic fever in the Democratic Republic of Congo in 2009. Before Predict’s work, these viruses were unknown to humans, their genomes a mystery despite their perilous potential.

For all its work, however, Predict had only just begun its exploration of viruses when, in October 2019, The New York Times reported that Trump’s USAID planned to shutter the program. The decision had been made not to renew it for a five-year funding cycle. Carroll was dismayed. He ultimately left the agency, telling the Times that Predict’s cancellation was a result of “the ascension of risk-averse bureaucrats” at USAID who were trying to divine the desires of an administration seen as hostile to experimental science abroad.

“I don’t think there was a directive from [the] White House saying, ‘Cancel Predict,’” said the EHA’s Daszak. “But I do think that the director of USAID and midlevel bureaucrats realized that Predict, which sent money to places like China to discover viruses, was a bit unusual for USAID.” In the age of America First, when the president wants to cut funding for essential public health institutions like the World Health Organization, a program like Predict wouldn’t fly. And so one of the first great global examples of One Health in action came to an early end just as a deadly coronavirus from bats was about to make its terrifying debut.

“To end this extraordinary work when the risk of new viral threats like Covid-19 [was] increasing was unconscionable,” Carroll concluded. And now “we are paying the consequences.”

There were many warning signs, many spillover events that anticipated the arrival of Covid-19. SARS, MERS, Ebola—in some sense, they were all opening acts. To this day, they are all on the WHO’s watch list of diseases that it says “pose the greatest public health risk due to their epidemic potential.” Somewhere on the list, too, is Nipah virus, a disease that is noteworthy because it is terrifyingly lethal and it so perfectly illustrates the way that human encroachment into wild spaces can unleash deadly plagues upon the world. With a case fatality rate that runs as high as 75 percent, Nipah virus infection remains “probably the worst disease that no one has ever heard of,” said Jonathan Epstein, an EHA scientist who has studied it extensively.

The virus first broke through in 1998, when people started dropping dead in Malaysia from a mysterious illness that caused devastating encephalitis, engorging the brains of the afflicted. It was primarily appearing on pig farms, and as the death toll climbed, fear spread that it could soon sprawl out of control. In 1998 and 1999, more than 260 people came down with the disease, and 105 perished. The culprit, scientists discovered, was a pathogen from the Paramyxoviridae family. Researchers, including scientists with the EHA, eventually uncovered the chain of transmission. It involved bats, fruit trees, pigs, and people.

The Nipah virus originated in fruit bats that had taken to raiding mango trees adjacent to animal enclosures on Malaysian pig farms. The virus emerged in a setting where wild animals, domestic livestock, and people were in intimate and consistent contact.

“Bats were coming in in large numbers, feeding on mangoes, and in the process of chewing on the mango, they would drop mangoes laden with saliva and other body fluids into the pig pens,” Epstein said. “That is how we believe it started.”

The virus invaded domestic pigs and then their human caretakers, and the rest is history. Ultimately, Malaysia killed nearly a million pigs across the country to stamp out the virus, and it implemented other biosecurity measures, like keeping swine in enclosures far from fruit trees and other food sources that might attract bats. Though Nipah outbreaks still occur regularly in places like Bangladesh, Malaysia has not had an outbreak since that first incident at the turn of the century.

The Malaysians “understand that the risk has to do with interaction between bats and pigs,” said Carroll, “and so they removed that risk.”

The story of Nipah in Malaysia is a classic One Health story, and it left an important legacy. The outbreak was an inspiration for the fictional pathogen in Steven Soderbergh’s film Contagion, which brought the concept of zoonotic spillover to a general audience. It also inspired a great deal of research, including a partnership among the Malaysian government, EHA scientists, and others to determine how common the virus is in bats and how regularly it passes into people. The response also showed that swift action can keep a virus in check, though nothing is guaranteed. Nipah is still out there. It has been there all along.

“There is still a risk of Nipah reemerging,” said Epstein, “and that is true not only in countries where we know there’s Nipah, like Malaysia and Bangladesh, but in other countries in Southeast Asia where people and bats cohabitate.”

Of course, this is the case with any virus circulating among wild species; spillover is a constant possibility. And the bats of Asia, the apes of Africa, and the rodents of Europe are not the only animals that naturally harbor potential human pathogens.

Though public narratives often emphasize the foreign origins of emerging diseases—Trump’s “China virus” rhetoric being a particularly toxic example—zoonotic spillover can happen right here in the United States. Consider Lyme disease, that scourge of summertime hikers, which emerged in degraded New England forests where growing human settlements scrambled habitats, upended ecosystems, and fueled outbreaks. West Nile virus, hantaviruses, and rabies have also made the leap from animal hosts to human bodies in this country. In fact, it was fear of just such a zoonotic spillover that took EHA scientists to Texas in 2013 to help protect an enormous bat cave.

The Bracken Cave Preserve is a natural wonder, home to a famous community of Mexican free-tailed bats. With some 20 million residents, it hosts the single largest population of bats in the world. It’s a vast metropolis of nocturnal winged mammals, all on the outskirts of fast-growing San Antonio.

In 2013 a real estate company unveiled plans to erect a sprawling residential complex near Bracken’s boundary. The venture was similar to many other big developments that rise around the country each year, gobbling up wildlife habitats and putting animals at risk. But this one involved bats. And if there is one group that is highly attuned to the dangers of zoonotic disease, it’s bat people.

“When this development was proposed, we became very concerned, because they were talking about putting up a dense urban sprawl kind of neighborhood, like four houses an acre,” said Mylea Bayless, the chief of strategic partnerships at Bat Conservation International, or BCI, which owns and manages the Bracken Cave Preserve. “We were looking at like 3,800 homes right under the flight path of the bats.”

BCI was concerned for the bats, of course. It didn’t want new neighbors to harass them or, God forbid, inadvertently start a fire in the cave, with its massive quantities of highly flammable guano. But the group was also worried about potential health threats to thousands of new human neighbors who would inevitably be exposed to the millions of bats next door—bats that might roost under their roofs, sip from their swimming pools, or carry the rabies virus or other possible pathogens, including a family of viruses with which we’re all too familiar: coronaviruses.

By sticking people in “the pathway of nature,” said Bayless, the proposed development was going to create a “human-wildlife conflict where none existed.”

So BCI turned to a sympathetic City Council member, Ron Nirenberg, who was also concerned about the impact the real estate project might have on the aquifer that supplies San Antonio’s drinking water. Together they solicited the services of the EHA, asking it to conduct an assessment of the potential health risks to people and animals if the development moved forward.

“I was incredibly excited by the project because it was so unique for a municipality…to even think in terms of ecological risk and health and development,” said Epstein, who led the EHA’s health assessment of the proposed development. “We were looking at not just the conservation risks or environmental risks but the health risks, too.”

He spent three months on the project, traveling to the area to study both the bats and the development site. In August 2013 he produced a report featuring rich details on bat ecology and disease ecology. He described the Mexican free-tailed bats of Bracken cave as the world’s “largest aggregation of bats, and possibly of any mammal other than humans.” He noted that the bats provide a huge service to Texas farmers each year by means of their “vast predation” of agricultural pests. He called the construction of a large-scale development next to such an enormous bat colony “unprecedented.” And he cautioned that the development would pose serious problems for the bats and for public health. Among other things, he warned of a possible uptick in rabies infections among humans and pets in the area and noted that coronaviruses and other pathogens are shed in bat fecal material, which could pose a health threat to residents. He found that local authorities should prepare for “an increase in demand of public health and animal control resources” if the development was approved.

The report had “an impact,” according to Nirenberg, who is now the mayor of San Antonio. “We wanted to illustrate the very real concern that people had for human health related to building homes near the largest concentration of bats in the world,” he said. Ultimately he, in partnership with BCI and numerous other parties, engineered a deal: They raised a cool $20.5 million and bought the property near the Bracken Cave from the developer. It is now preserved in perpetuity.

“It is a truly inspiring story,” said Bayless, “because it went from the crazy bat people jumping up and down screaming ‘Save the bats’ to it being this really complex, carefully brokered deal that included city government, county government, two nonprofits, the public water utility.”

The One Health Movement has scattered seeds across the planet, and they are now sprouting. Governments and international institutions are moving to practice its precepts. Scientific silos are slowly breaking down. In October, for instance, a prestigious UN-affiliated body of international scientists issued a report on biodiversity and pandemics that called on national governments to begin “institutionalizing One Health” and thereby put an end to this “Pandemic Era.”

Some governments have already made headway, including China, which is piloting a World Bank–backed program in the provinces of Hainan and Jiangxi that seeks to identify potential spillover hot spots and reduce contact between humans and high-risk wildlife, among other goals. The United States has a smattering of relevant programs too, including a One Health office at the CDC and a One Health program at the National Park Service, which studies and responds to zoonotic disease threats on park lands, including hantavirus and Yersinia pestis, which causes the plague.

One Health advocates, meanwhile, are pushing for more action fast. In September, Karesh, Machalaba, and their colleagues called for the creation of a “global wildlife health authority”—an intergovernmental agency akin to the WHO that would help countries across the world “manage disease threats to and from wild animals, including at the interface between human, domestic animal, and wild animal populations.” Currently no such body exists.

Closer to home, advocates would like to see Joe Biden’s incoming administration establish a high-level task force to coordinate a pan-agency One Health mobilization to combat environmental degradation, infectious disease emergence, and the many chronic noncommunicable illnesses fueled by pollution.

Still, acute interventions like these are only a start. Many scientists believe more profound societal transformations are required if we are to avoid a future filled with outbreaks, epidemics, and pandemics, not to mention mass animal extinctions and the ravages of global climate change. Daszak said human society needs a “complete realignment of our relationship with nature” that will involve everyone on the planet.

“Rich countries are far removed from the origins of these pandemics,” he added, “but they are driven by us.” The activities that cause deadly outbreaks are the same activities that give us the “palm oil in every food product,” the “metals in our phones,” and “the fur trim on our winter jackets”; they are the wildlife trade, the mining industry, industrial meat production, industrial agriculture, fossil fuel production, urban sprawl—all the things that tear up animal habitats, wipe out species, and put humans, livestock, and wildlife in abundant contact.

To take One Health to its logical conclusion would mean truly confronting these forces of commercial expansion and exploitation. It could mean a massive reduction of livestock production, which plays a key role in both the extinction crisis and the emergence of novel infectious diseases. It could mean an end to the commercial wildlife trade. It could even mean a global embrace of eminent biologist E.O. Wilson’s Half-Earth idea, his plea to set aside half of the planet’s surface as a preserve for wildlife in a last-ditch attempt to avoid broad biodiversity collapse.

Of course, any transformation of this magnitude would inevitably face backlash. Industry interests almost always chafe when forced to comply with laws and regulations that constrain commercial development. “The impediments to One Health in the past and moving forward are entrenched economic interests,” observed Susan Lieberman, a vice president at the Wildlife Conservation Society, a leader in the One Health movement.

Still, despite the obstacles, the movement has momentum, its embrace spurred by the kind of lethal global outbreak it strives to prevent. Even Trump has had limited success undermining the movement’s work. In August, after fierce public denunciations of its decision to cancel the EHA grant, the NIH awarded more than $80 million to the EHA and other groups to create a network of research centers to study emerging infectious diseases around the world. USAID, meanwhile, is reviewing applications for a new international program to combat zoonotic disease. The program, called Strategies to Prevent Spillover, is not the same as Predict, but it does aim to develop rapid response interventions in zoonotic hot spots in order to head off outbreaks. Biden, meanwhile, has repeatedly promised to revive Predict after he takes office.

Overall, Daszak says, he’s optimistic about the future of his organization and the wider One Health movement. He vows to return to China as soon as possible to continue the stalled coronavirus research there. Amid the carnage of Covid-19, he says, “We will drive momentum forward and do even more…so we can prove we can stop a pandemic.”