Yale report (2020) showed us that children’s immune response was way more effective against COVID-19 than adults; Children & adults exhibit distinct immune system responses to infection by the virus

by Paul Alexander

Interleukin 17A (IL-17A) & interferon gamma (INF-g) are key to the puzzle as to why kids do so well against COVID virus; strongly linked to the age; younger (kids) had higher innate IL-17A & INF-g

A Yale report in 2020 was one in many that showed us the potency and robustness of children’s innate immune response to COVID virus and why they did so well against the virus. ‘Specifically, researchers looked for variations in the types of immune system responses in patients who experienced different health outcomes from the novel coronavirus. The subjects also included children and adolescents diagnosed with multi-system inflammatory syndrome or MIS-C, a rare complication of COVID-19 infection in young people that is associated with a variety of severe health complications.

They found that levels of two immune system molecules — interleukin 17A (IL-17A), which helps mobilize immune system response during early infection, and interferon gamma (INF-g), which combats viral replication — were strongly linked to the age of the patients. The younger the patient, the higher the levels of IL-17A and INF-g, the analysis showed.


These two molecules are part of the innate immune system, a more primitive, non-specific type of response activated early after infection, Kevan Herold noted. Conversely, the adults showed a more vigorous adaptive immune system response including higher neutralizing antibody levels, which record signatures of pathogens and target them for elimination.

They also found that children with rare cases of MIS-C also have high levels of IL-17A and INF-g, but seldom exhibit severe damage to lung tissue that characterizes severe adult cases. These children, however, share other immune response signatures linked to more severe adult cases. The source of the IL-17A and INF-g molecules remain unknown, but its identification may shed light on cells that can be targeted to prevent severe effects from COVID-19. 

Boosting certain types of immune responses may be beneficial to patients, the authors theorize.

“The suggestion is that kids have a more robust, earlier innate immune response to the virus, which may protect them from progressing to severe pulmonary disease,” Betsy Herold said.’