Children’s noses pack a punch that could help explain COVID-19’s typically mild course in young kids. Researchers hope to parlay that ‘nasal magic’ into increased protections for adults. As a rule, infants and young children rarely develop severe or enduring cases of COVID-19. And those who do almost invariably suffer from some other serious medical problem. It’s not that kids don’t get infected. They do. More than 90% of kids age 4 and under in the United States test positive for previous or current infection by SARS-CoV-2, the coronavirus that causes this respiratory infection. Yet, although kids under 5 represent about 6% of the U.S. population, they account for fewer than 0.1% of COVID-19 deaths in this country. Researchers are intent on finding out why.