Researchers at Albert Einstein College of Medicine, Montefiore Health System, and Yale University have established for the first time that, in response to infection with the novel coronavirus, children mount a stronger innate immune response than adults. This difference in innate immunity (which involves immune-cell activation against viruses and other pathogens) was also linked to outcomes, with children experiencing much milder cases of COVID-19 compared with adults.

The study, published online on April 6 in JCI Insight, involved 12 children and 27 adults seen at the Montefiore Medical Center emergency department who tested positive for coronavirus infection. Swabs were used to obtain fluid and cells from patients’ nasal mucosa, the site where the coronavirus is believed to first encounter the human body. Using RNA sequencing to assess gene expression, the researchers found that children expressed higher levels of genes associated with immune cells and with several protective cytokines (proteins secreted by immune cells). In addition, assessment of cytokine levels in nasal fluid showed higher levels in pediatric patients compared with adults.

None of the 12 children in the study required oxygen, while seven of the 27 adults needed oxygen and four of them died. The findings suggest that strategies for bolstering innate immunity might help in treating severe COVID-19 disease.

The study’s co-senior authors were Betsy Herold, M.D., chief of infectious diseases and vice chair for research in the department of pediatrics at Einstein and the Children’s Hospital at Montefiore; and Kevan C. Herold, M.D., C.N.H. Long Professor of Immunology and of Medicine at Yale School of Medicine.