Age-related changes in the upper respiratory microbiome influence SARS-CoV-2 susceptibility and severity

Children appear to be less susceptible to SARS-CoV-2 infection, and SARS-CoV-2-infected children typically have milder illness courses than adults. We sought to evaluate the role of the upper respiratory microbiome in the clinical courses of children and adolescents exposed to SARS-CoV-2. To accomplish this, we studied the nasopharyngeal microbiomes of 274 children and adolescents (<21 years of age) with SARS-CoV-2 exposure using 16S ribosomal RNA sequencing. We then evaluated associations between nasopharyngeal microbiome features and SARS-CoV-2 infection. Among SARS-CoV-2-infected children, we additionally evaluated associations between nasopharyngeal microbiome features and SARS-CoV-2.