One of the most perplexing elements of the novel coronavirus is its variability. It’s common knowledge that while many infected people will experience mild symptoms, those who are older, male and have underlying chronic disease are at much higher risk of severe disease and death.
Two recent papers published in Science provide some of the most compelling evidence behind the impaired immune response seen in severely affected patients—and a potential link to the gender disparities in outcomes.
Both papers are centered on the role of Type I interferon, an immune protein that provides a first line of defense in viral illness.
The first study analyzed the DNA of over 650 patients with severe COVID to assess mutations in the genes that code for interferon-1. Some 3.5 percent of patients with life-threatening COVID carried mutations, but these were found in none of the control patients who only had mild disease.
The second paper evaluated the presence of antibodies to the patient’s own interferon, finding that 14 percent of patients with severe disease had these “auto-antibodies”, which are extremely rare in the general population. Interestingly, 12.5 percent of severely ill men had the antibodies, compared to just 2.6 percent of women with severe disease. Previous work linked poor interferon response to the X chromosome, highlighting the potential increased risk for men.
Taken together, these studies indicate that impaired Type I interferon could contribute to 1 in 7 severe COVID cases. Scientists are hopeful this work could lead to new diagnostics that estimate a patient’s risk of poor outcomes. This growing body of work, with new insights published every week in Science and other journals, underscores the rapid advances being made in understanding and treating this novel and complex disease.