Cepon-Robins illustrates how immune responses to intestinal parasites could reduce severity of COVID-19

A colorful map of U.S. COVID-19 cases. Photo credit: Brian McGowan, Unsplash.

Humans may be able to dampen the worst effects of COVID-19, writes Tara Cepon-Robins, assistant professor of anthropology, in a new review article. We just need a little help from some old friends: parasitic intestinal worms.

As Cepon-Robins explains in the paper – co-written with Theresa Gildner, assistant professor of anthropology for Washington University in St. Louis, and published by Evolution, Medicine and Public Health journal – humans share a long coevolutionary history with parasites like intestinal worms. In fact, an entire branch of the human immune system evolved not to fight back against parasites entirely, but to peacefully cohabitate with them.

An image taken via microscope of a Trichuris trichiura (whipworm) and Ascaris lumbricoides (giant roundworm) coinfection. Image credit: Tara Cepon-Robins.

Cepon-Robins and Gildner hypothesize that this immune system branch, when stimulated by parasites, could suppress inflammatory immune activity, thereby potentially reducing the severity of COVID-19 symptoms.

The paper, titled “Old Friends Meet a New Foe: A potential role for immune-priming parasites in mitigating COVID-19 morbidity and mortality,” studies whether the presence of soil-transmitted helminths – a common intestinal parasitic worm – causes human immune systems to reduce inflammation and decrease risk for inflammatory disorders like cardiovascular disease, autoimmunity and allergies.

Reducing the inflammatory response to COVID-19 could have a critically important role, the paper explains, because the most severe symptoms associated with COVID-19 are overactive inflammatory immune responses. If left uncontrolled, those responses lead to cytokine storms, tissue damage and death.

Though further research must be conducted, Cepon-Robins and Gildner conclude that the coexistence of a parasitic infection and COVID-19 could work to reduce the virus’s morbidity and mortality.

An image taken via microscope of a soil-transmitted helminth egg. Image credit: Tara Cepon-Robins.

“When we first started learning about COVID-19, it became clear that the worst health outcomes occurred in people with inflammatory comorbidities, including heart disease, diabetes and autoimmunity,” Cepon-Robins said. “This inspired us to propose an immune pathway by which soil-transmitted helminths might also help to protect people from the worst COVID-19 outcomes.”

“We hope this paper will inspire more research on the effects that soil-transmitted helminths might have on COVID-19 in endemic areas,” she continued. “It is crucial that we work to understand the effects that these parasites may have on COVID-19 outcomes if we want to thoroughly understand the global impacts of the virus.”

Cepon-Robins conducts research among the Shuar of Amazonian Ecuador with the Shuar Health and Life History Project and in her own recently-developed project in the southeastern United States, the Rural Embodiment and Child Health Project. Her research combines technologies from microbiology, genetics and anthropology to understand the role that bacterial and helminth exposure play in immune function, growth, development and health. Read more about her research.

Cepon-Robins is the first UCCS Boettcher Investigator in the Webb-Waring Biomedical Research Program, and the first anthropologist to earn the honor since the Boettcher Foundation established the program in 2010.