Most children infected with SARS-CoV-2, the virus that causes COVID-19, develop only a mild illness. But, days or weeks later, a small percentage of kids go on to develop a puzzling syndrome known as multisystem inflammatory syndrome in children (MIS-C). This severe inflammation of organs and tissues can affect the heart, lungs, kidneys, brain, skin, and eyes.
Thankfully, most kids with MIS-C respond to treatment and make rapid recoveries. But, tragically, MIS-C can sometimes be fatal.
With COVID-19 cases in children having increased by 21 percent in the United States since early August [2], NIH and others are continuing to work hard on getting a handle on this poorly understood complication. Many think that MIS-C isn’t a direct result of the virus, but seems more likely to be due to an
intense autoimmune response. Indeed, a recent study in
Nature Medicine [1] offers some of the first evidence that MIS-C is connected to specific changes in the immune system that, for reasons that remain mysterious, sometimes follow COVID-19.