Climate change, expanding human populations, and other global changes are increasing opportunities for humans and animals to interact, accelerating the spread of viruses to humans. While the virus that causes COVID-19 was devastating, it continues along with new threats such as the present global outbreak of the H5N1 influenza virus.
The recent outbreak of an emergent strain of H5N1 — often called bird flu — spans multiple continents and has had an enormous ecological impact posing a threat to numerous wild bird species. Spillover into poultry around the world has necessitated the destruction of millions of domestic birds, severely challenging the poultry industry and threatening food security. What makes this strain of H5N1 virus of greater concern is the infection of more than 30 mammalian species that has probably killed thousands of marine mammals. Such spillover from birds to mammals creates the opportunity for viral adaptation to mammalian hosts, which can open the door to infection of humans.
The scope and character of the present H5N1 outbreak are alarming, but this is only one virus. There are many more known and as-yet undiscovered viruses in wildlife that pose threats to domestic animals and humans. The COVID-19 pandemic showed us that viruses can rapidly change and adapt. However, advanced knowledge of viruses that pose a danger can avert outbreaks in humans. This knowledge is gained by worldwide surveillance and field research, which are critically needed to define where and how a suspect virus is circulating geographically, how it’s evolving, and where and how new species — including humans — may become exposed. Without such insights, options to prepare for or prevent a pandemic are challenging if not improbable.
Despite the importance of surveillance and field research, some feel that their risks outweigh benefits and want this work to be stopped. Their reasoning is that interactions with wildlife as part of scientific study provide an opportunity for spillover to humans. Others advocate for changes such as federal department-level review of much pathogen research in the United States, including surveillance and field studies. Through increased bureaucratic burden, these changes could hamstring research that is essential to pandemic preparedness and outbreak response.
Indisputably, research safety is important and needs to be applied consistently, as well as reviewed and updated regularly as science and technology progress. But given the value of pathogen research to public health, safety measures should be designed to minimize risk while allowing beneficial science to proceed. Those focused on eliminating risk entirely would ban scientists from sampling wildlife and characterizing animal pathogens. But extensive interaction with wildlife through hunting, mining, tourism, and many other fundamental human activities will continue. Banning the science would win a battle on perceived lab safety but lose the war against the threats of nature.
The ongoing H5N1 outbreak offers an example of the critical need for surveillance and field research. Based on rapid investigations in the field, decisions are being made in real time about restricting public access to wildlife areas, how animals are housed and handled in businesses, and how animal carcasses are disposed of. At the same time, biologists’ field efforts characterize the breadth and effects of variant viruses in wildlife and furnish samples, which are directly applied to selection of vaccines for pandemic preparedness and assessment of antiviral therapeutics. Without the information gained from research in the field, such precautions and preparation are not possible — instead of finding a virus and containing its threat, we would be waiting for the virus to find us and relying on luck and fortune to respond in time. As COVID-19 proved, detection after emergence can be too late to prevent a pandemic.
“Virus hunting” is often portrayed in the media as risky. Yet, pathogen research in the field — as in the lab — is subject to thorough oversight. In the United States, proposed field studies undergo review by institutional biosafety committees that are mandated and guided by federal agencies. Interactions with wildlife are included in this review. Research teams are trained and advised on prevention of potential zoonotic infections, including vaccination where appropriate and the use of personal protective equipment. Often, field studies require involvement, permission, and oversight by local, state, and/or federal government bodies. All field sites are unique, but awareness, training, and preparation can ensure that samples, wildlife, and personnel are protected and secure.
The health of humans and animals is deeply interconnected across global shared environments. Turning a blind eye to viruses in animals will not stop them from spilling over into humans. On the contrary, the accelerating rate of viral zoonoses — the spread of viruses from animals to humans — calls for a reinvigoration of research designed to identify and understand nature’s biological threats. Only by knowing our enemy can we prepare our defenses and prevail.
Jonathan Runstadler is a virologist at Tufts University. Anice Lowen is a virologist at Emory University.