Although such findings are illuminating, using organoids to study the virus–host interaction is in its infancy, says Haagmans, who developed the gut organoids. “It is too early to say how relevant they are,” he says. More complex organoid systems are needed to better understand how the virus interacts with the body’s immune system to cause damage, say researchers.
“We are fairly confident now that the virus that causes COVID-19 can infect tissue outside the lung and significantly contribute to disease,” says Penninger. But more severe outcomes, such as kidney and heart damage, are probably due to a combination of viral infection and an excessive immune response, he says.