Though these patients often have health conditions like diabetes that compound their risk, scientists have become increasingly convinced that their vulnerability has something to do with obesity itself.

Now researchers have found that the coronavirus infects both fat cells and certain immune cells within body fat, prompting a damaging defensive response in the body.

“The bottom line is, ‘Oh my god, indeed, the virus can infect fat cells directly,’” said Dr. Philipp Scherer, a scientist who studies fat cells at UT Southwestern Medical Center in Dallas, who was not involved in the research.

“Whatever happens in fat doesn’t stay in fat,” he added. “It affects the neighboring tissues as well.”