Do Children's Noses Protect Them Against COVID-19?

It's common for children to be sick more often than adults. In fact, the Mayo Clinic reports that it is typical for children to have around 12 colds and up to seven ear infections per year. Sometimes, symptoms can last as long as two weeks, and a cough can last up to six weeks. When it comes to COVID-19 infections, however, research shows something different happens with children.

Overall, children have lower infection rates for COVID, and they also seem to experience milder symptoms, according to 2020 research published in The New England Journal of Medicine. However, experts couldn't really come up with a reason why. That said, new research published in PLOS Biology may shed light on why COVID affects children differently. For the small study, researchers compared samples of cells from the nasal lining of 23 healthy children and 15 healthy adults who were exposed to the COVID virus.

The key to fewer COVID infections may be in the lining of children's noses. The Australian study showed that the lining of children's noses has a "more pro-inflammatory response to the ancestral SARS-CoV-2 than adult noses." This means that the virus did not reproduce in children's noses as well as it did in adults. However, the difference was less detectable in cases of Omicron infections.

Kirsty Short, one of the authors of the study, explained that a reason why this might happen could be an adaptation of foreign threats, such as bacteria and viruses. Another reason may be that increased exposure to threats "trains" the nasal lining to produce a stronger pro-inflammatory response. An additional possibility could be related to metabolic differences between children and adults. The researchers also noted that while this study supported the idea that the linings of children's noses might lower the rate of infection, this could change as the virus evolves. They also acknowledged that a study examining a larger portion of the population is necessary to corroborate the findings.