An immune protein could prevent severe COVID-19 -- if given at the right time

Several new studies of immune response to SARS-CoV-2, the virus that causes the disease, suggest timing could be critical for a class of proteins known as interferons, which are being researched as potential treatments. These immune proteins suppress viral replication early in disease. Yet if they are active later, some scientists think they can exacerbate the harmful inflammation that forces some COVID-19 patients onto life support. Interferons are “a double-edged sword,” says immunologist Eui-Cheol Shin of the Korea Advanced Institute of Science and Technology.

Researchers have been looking at both of that sword’s edges. About a decade ago, when Shin was studying the viral disease hepatitis C, interferons were used as a standard treatment. But examinations of some conditions suggested they should not be employed. For example, researchers in Paris found that too much of the proteins can lead to a diseases known as children’s interferonopathies. In a sense, each of these two perceptions of interferons is correct. And understanding when, and to what extent, using them is warranted could be a critical factor in treating COVID-19.