This Is How Covid Started. And Here’s How We Stop the Next One.

“That is the kind of thing that keeps me up at night.”

Making sure that people have enough safe food is also important part of the discussion. When international outlets first started covering Covid-19, many pointed fingers (inaccurately) at Chinese culinary habits and called for wildlife bans, even though it’s still unclear whether the virus emerged from wild or domesticated animals. “The last thing I want to see is a focus on the people at the bottom of the ladder here who are trying to make a living for their families,” Worobey said. Instead, we should focus on “the systems that can lead to this”—poverty, hunger, resource extraction.

Covid-19 has also illuminated the pressing issue of “spillback,” a phenomenon that is less understood. Spillover occurs when a virus moves from animals to humans, but spillback is when viruses move from people to animals and back to people, evolving along the way. New research in Canada indicates a highly mutated version of SARS-CoV-2 in white-tailed deer may have now passed into people. “New variants can emerge from circulation in populations of wild animals—and it was striking to me how much that [deer variant] actually looked, in some ways, similar to omicron, where it was this completely different evolutionary branch that this variant was a part of,” Rasmussen said. “What if the next omicron comes out of an animal population and is actually more pathogenic or potentially even more transmissible? What if it’s distinct enough, from an immunological perspective, that it is not only capable of evading the protection that vaccines provide against infection but also the protection that they provide against severe disease? That is the kind of thing that keeps me up at night.”

Above all, we need to understand that viruses can and will surprise us—but being prepared for as many potential scenarios as possible can lessen many of those surprises. “If there’s anything that this pandemic has taught me, it’s to have some humility about what can and cannot happen,” Rasmussen said. Two years into this devastating outbreak, research and monitoring of zoonotic spillover and viral emergence has “only just scratched the surface. What else are we going to find if we start looking harder? And I think we absolutely need to start looking harder.”