How does COVID-19 affect kids? Science has answers and gaps

What role children play in the coronavirus pandemic is the hot-button question of the summer as kids relish their free time while schools labor over how to resume classes.

The Trump administration says the science “is very clear,” but many doctors who specialize in pediatrics and infectious diseases say much of the evidence is inconclusive.

“There are still a lot of unanswered questions. That is the biggest challenge,” said Dr. Sonja Rasmussen, a pediatrics professor at the University of Florida and former scientist at the U.S. Centers of Disease Control and Prevention.

Several studies suggest, but don’t prove, that children are less likely to become infected than adults and more likely to have only mild symptoms.

An early report from Wuhan, China, where the outbreak began last winter, found that fewer than 2% of cases were in children. Later reports suggest between 5% and 8% of U.S. cases are in kids.

Through July 9, about 200,000 kids had tested positive in the U.S., according to a count based on state reports by the American Academy of Pediatrics. The number of kids who have been infected is almost certainly far higher than that though, experts say, because those with mild or no symptoms are less likely to get tested.

The CDC says that 228 children and teens through age 17 have died from the disease in the U.S. as of Thursday. More than 138,000 Americans have died in total, and there have been more than 3.6 million confirmed cases.

One early study examining infections in children comes from a Wuhan hospital. Of 171 children treated there, most had relatively mild illness. One child died, and only three needed intensive care and ventilator treatment. Perhaps more worrisome was that 12 had X-ray evidence of pneumonia, but no other symptoms.

A CDC study...