Preliminary analysis of scRNA sequencing of children’s lung tissues excludes the expression of SARS-CoV-2 entry related genes as the key reason for the milder syndromes of COVID-19 in children

To explore whether the expression levels of viral-entry associated genes might contribute to the milder symptoms in children, we analyzed the expression of these genes in both children and adults’ lung tissues by single cell RNA sequencing (scRNA-seq) and immunohistochemistry (IHC). Both scRNA-seq and IHC analyses showed comparable levels of the key genes for SARS-CoV-2 entry in children and adults, including ACE2, TMPRSS2 and FURIN, suggesting that instead of lower virus intrusion rate, other factors are more likely to be the key reasons for the milder symptoms of SARS-CoV-2 infected children.