Covid-19, Editoriale

One in Seven Dire COVID Cases May Result from a Faulty Immune Response

Perhaps the most unnerving aspect of COVID-19 is its startling range of severity: from completely asymptomatic to deadly. Starting early in the pandemic, researchers identified factors that put people at risk of a serious case of the disease, such as advanced age, having certain chronic diseases and being male. But these demographic trends do not get at the biological mechanisms that actually cause a life-threatening infection. Nor do they explain why some young, fit, healthy people become mortally ill from the SARS-CoV-2 virus.

Two related papers published in Science on September 24 begin to address these mysteries. They may also partially account for men’s greater vulnerability to the virus and point the way to possible treatments and protective measures. Both studies highlight the critical role of a class of immune system proteins called interferons, so named because they interfere with the replication of viruses.

The new papers were produced by the COVID Human Genetic Effort, a huge international consortium of researchers hunting for genetic mutations that either make individuals unusually susceptible to SARS-CoV-2 or confer exceptional resistance. The consortium is co-led by Jean-Laurent Casanova of the Rockefeller University and Helen Su of the National Institute of Allergy and Infectious Diseases, who are co-senior authors of both of the studies…