SARS-CoV-2 entry related genes are comparably expressed in children's lung as adults

To explore whether the expression levels of viral-entry associated genes might contribute to the milder symptoms in children, we analysed 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 expression 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.