Study: Black and white ancestral origins show no difference in susceptibility to COVID-19

Dr. Cuong Nguyen, an associate professor in the UF College of Veterinary Medicine’s department of infectious diseases and immunology, in his laboratory.

By Sarah Carey

Whether your ancestors were Black or white makes no difference in your susceptibility to COVID-19, according to a new University of Florida study comparing two types of ancestral origins of patients from a Florida population infected with COVID-19.

However, UF researchers also found that some patients, whose genetic makeup gives them more protection against SARS-CoV-2 proteins, have a better chance of fending off infection from the virus.

The data amassed in their investigation, published in January in PLOS One, could be useful in developing customized vaccines to boost immunity among the European and African American ancestral groups studied as well as potentially other groups, said the study’s lead author, Cuong Nguyen, Ph.D., an associate professor of infectious diseases in UF’s College of Veterinary Medicine who studies how the immune system responds to autoimmune diseases in people. The college is part of UF Health, the university’s academic health center.

The researchers embarked on the study to better understand why clinical symptoms of the disease are so varied among patients, with some exhibiting severe symptoms and others showing few or no symptoms at all, Nguyen said.

“In the early part of the pandemic, we knew we had to get health care professionals back to work, but we didn’t know what the risk factors of infection with SARS-CoV-2, the virus that leads to COVID-19, were,” Nguyen said. “Say you were a dentist or a nurse. What would be the risk of you becoming exposed in the health care environment? We wanted to look more in-depth at the immune system to see if some people were more naturally protected than others.”

Nguyen’s team studied 284 confirmed COVID-19 patients and used 95 healthy individuals as controls. They examined cases and controls from European and African American ancestry.

“We learned that there is really no difference between types in terms of whether someone is prone to be infected or not,” he said.

Each human has DNA, which contains our unique genetic code. For every characteristic that makes us different — short or tall, brown eyes or blue, curly hair or straight — we all inherit two alleles, one from each parent. Some of our alleles determine whether we have more or less protection when we make contact with the COVID-19 virus.

“If that allele is protective, you have more antigens, so you respond better to the virus,” Nguyen  said. “But even if someone has the at-risk allele, we could deliberately tailor the viral proteins that would elicit a protective immune response. With results from this study, our goal is to be able to design a vaccine that the immune system recognizes as protective based on the human leukocyte antigen, or HLA, alleles.”

The ideal vaccine would be customized to genetic types and would act by essentially cutting the COVID-19 virus protein into pieces, Nguyen said.

“Once we understand someone’s genetic makeup better, we can design a more effective vaccine, especially for breakthrough COVID-19 infection,” he added.