When children are infected with COVID-19, their innate immune system mobilizes against the virus more effectively than adults, Wall Street Journal reported 21 Feb.
This is a likely factor behind why children often do better with a COVID-19 infection than adults, scientists told the Journal, explaining how the immune system has multiple layers of defense. Congenital immunity is the first line of defense that coordinates the initial response to an infection. It includes mucus in the nose and throat that helps capture harmful microbes, as well as proteins and cells that trigger the initial reaction. Adaptive immunity is the slower growing second line of defense involving T cells and B cells.
That Journal quoted research who found that children’s immune systems have higher levels of some innate molecules and increased innate reactions compared to adults. The study compared 65 young patients and 60 adults infected with COVID-19 in New York City during the first few months of the pandemic. Study authors Kevan Herold, MD, professor of immunobiology and internal medicine at New Haven, Conn.-Based Yale University, and his wife Betsy Herold, MD, a pediatric infectious disease physician at the Montefiore Children’s Hospital in the Bronx borough of New York City, said children were less dependent on the adaptive immune system than adults, probably because their innate response was stronger. Nose and throat swabs also showed that several genes involved in innate immunity were activated in children.
Experts were concerned that the overall tendency for children in general to do better than adults through the pandemic would deter parents from getting their children vaccinated, experts warned that some children get seriously ill from COVID-19 and emphasized the risk of multisystem inflammatory syndrome, a rare but serious condition associated with COVID-19.
“The innate barrier is not 100 percent protective,” said Dr. Betsy Herold.