Children have mild severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) confirmed disease (COVID-19) compared to adults and the immunological mechanisms underlying this difference remain unclear. Here, we report acute and convalescent innate immune responses in 48 children and 70 adults infected with, or exposed to, SARS-CoV-2. We find clinically mild SARS-CoV-2 infection in children is characterised by reduced circulating subsets of monocytes (classical, intermediate, non-classical), dendritic cells and natural killer cells during the acute phase. In contrast, SARS-CoV-2-infected adults show reduced proportions of non-classical monocytes only. We also observe increased proportions of CD63+ activated neutrophils during the acute phase to SARS-CoV-2 in infected children. Children and adults exposed to SARS-CoV-2 but negative on PCR testing display increased proportions of low-density neutrophils that we observe up to 7 weeks post exposure. This study characterises the innate immune response during SARS-CoV-2 infection and household exposure in children. Childhood infection with SARS CoV2 is associated with a milder course of infection but the immunopathogenesis of this remains unclear. Here the authors explore immunological differences in the innate immune system during acute and convalescent SARS CoV2 infection in the young.
【저자키워드】 SARS-CoV-2, Infectious diseases, Innate immunity, Infection, 【초록키워드】 COVID-19, Neutrophils, Monocytes, coronavirus, innate immune response, SARS-COV-2 infection, children, neutrophil, dendritic cells, monocyte, Non-classical monocytes, innate immune system, PCR testing, immune responses, Immunopathogenesis, Mild, Natural killer cells, respiratory, convalescent, disease, dendritic cell, Activated neutrophils, natural killer cell, immunological mechanism, acute respiratory syndrome, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, acute phase, low-density, circulating, mild SARS-CoV-2 infection, CD63, infected children, immunological, observé, Course, classical, proportion, clinically, reduced, subset, activated neutrophil, non-classical monocyte, 【제목키워드】 children, Innate, convalescent phase, cell profile,