Clonal dynamics of SARS-CoV-2-specific T cells in children and adults with COVID-19

Abstract

Children infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) develop less severe coronavirus disease 2019 (COVID-19) than adults. The mechanisms for the age-specific differences and the implications for infection-induced immunity are beginning to be uncovered. We show by longitudinal multimodal analysis that SARS-CoV-2 leaves a small footprint in the circulating T cell compartment in children with mild/asymptomatic COVID-19 compared to adult household contacts with the same disease severity who had more evidence of systemic T cell interferon activation, cytotoxicity and exhaustion. Children harbored diverse polyclonal SARS-CoV-2-specific naive T cells whereas adults harbored clonally expanded SARS-CoV-2-specific memory T cells. More naive interferon-activated CD4+ T cells were recruited into the memory compartment and recovery was associated with the development of robust CD4+ memory T cell responses in adults but not children. These data suggest that rapid clearance of SARS-CoV-2 in children may compromise their cellular immunity and ability to resist reinfection.

Infection and vaccine induced Spike antibody responses against SARS-CoV-2 Variants of concern in immune naïve children and adults

“…Similar to other studies [7,15], our data show that humoral immunity generated from SARS-CoV-2 appears not to be compromised in children. Age-related differences in immunity are not accounted by humoral responses, alternatively, rapid elimination of the virus in children may be due to higher pre-activated innate immune system [44][45][46]. The primary immunogenic domain of the Spike protein is the RBD [2,3].…”