On March 24 2019, Chinese anti-smuggling customs officials in Guangdong intercepted an illegal transport of 21 sickly pangolins and transferred them to a nearby wildlife rescue center where the majority later died. The rescue center workers discovered that nearly all of the dead pangolins had swollen lungs containing a frothy liquid, and some had enlarged livers and spleens. Using samples taken from the lung fluid, scientists at the wildlife center analyzed the contents and published their results in October 2019, identifying a new coronavirus infection.
Later genetic analysis of the new pangolin coronavirus revealed that the virus had spike proteins that were similar to the spike proteins on the SARS-CoV-2 virus causing COVID-19 in humans. These spike proteins are like keys that unlock ACE-2 receptors, allowing the virus to enter cells and replicate. Without them, the SARS-CoV-2 virus would not be as pathogenic for humans.
Spike proteins are not found on the ancestral bat version of the human SARS-CoV-2 virus, so how did they end up on the human virus? Although we do not know the exact pathway of the genetic evolution of the human version of SARS-CoV-2, scientific evidence overwhelmingly supports the idea that the human virus evolved through natural processes and was not bioengineered. Regardless of whether or not the ancestral bat virus accidentally leaked from a lab, the virus likely encountered at least one or more other animal hosts, such as a pangolin, within which it evolved before jumping to a human. A recent early release published online by the US Centers for Disease Control and Prevention supports this theory.
In addition to working on vaccines and treatments for these diseases, we must begin to think differently and conceive of a new solution: preventing pathogens from spreading from animals to humans in the first place.
There are many opportunities throughout the chain that supplies wild animals and their parts for human consumption where a bat coronavirus could jump to another species and encounter another coronavirus to further its evolution. In wildlife sections of wet markets, restaurants, trader warehouses, commercial breeding farms, and while in movement among trade nodes, wild animals are closely confined under stressful and unsanitary conditions. This leaves them injured, stressed, weak, and immunocompromised, creating the perfect conditions for viruses to jump among species and then to humans upon slaughter and consumption.
The COVID-19 pandemic caused by SARS-CoV-2 is just the latest in a long history of infectious diseases that have been traced to viruses jumping the species barrier from wild animal to human as a result of trade and consumption: Ebola (bats); MERS (bats/camels); SARS (civet cats/bats); and HIV (chimpanzees). Even the H1N1 swine flu in 2009 was a fourth-generation descendant of the Spanish Flu of 1918, which was an avian flu originating in wild birds.
In addition to working on vaccines and treatments for these diseases, we must begin to think differently and conceive of a new solution: preventing pathogens from spreading from animals to humans in the first place. There are many approaches we could take, but the easiest and fastest—the low-hanging fruit—is to dismantle the commercial wild animal trade, especially in terrestrial mammals and birds. This cause already has support among the Chinese government and most Chinese citizens, as well as among governments and citizens across other hotspot countries in Southeast Asia where the wild animal trade is active.
The value of the entire commercial wild animal trade worldwide is estimated to only be in the tens of billions, whereas the economic destruction due to this current pandemic alone has already totaled in the many trillions. The global economy should not be forced to be exposed to these risks. It is true that dismantling the trade will create economic hardship for some, but it is possible to help those affected find alternative livelihoods.
The reality is that this pandemic could be prolonged if a new SARS-CoV-2-like virus—circulating in an animal host right now—jumps the species barrier to a human yet again. To reduce this risk, I have helped mobilize a coalition to end the commercial trade in terrestrial wild animals. This coalition, managed by Global Wildlife Conservation, WildAid, and Wildlife Conservation Society, and with the backing of over 200 additional organizations, has three main strategies: monitor the existing terrestrial wild animal trade for pathogens, cut off legal and illegal supply chains, and reduce consumer demand including through education campaigns led by public figures. The coalition launched on April 20, 2020, with an announcement of support from the European Union. Later that day, Leonardo DiCaprio urged the world to join him in signing the coalition’s Declaration to End the Trade at www.endthetrade.com.
We must ensure that a preventable pandemic never happens again.