VIROLOGICAL AND IMMUNOLOGICAL FEATURES OF SARS-COV-2 INFECTED CHILDREN
WITH DISTINCT SYMPTOMATOLOGY
Abstract
BACKGROUND: Despite SARS-CoV-2 immunizations have started in most
countries, children are not currently included in the vaccination
programs, thus it remains crucial to define their anti-SARS-CoV-2 immune
response in order to minimize the risk for other epidemic waves. This
study seeks to provide a description of the virology ad anti-SARS-CoV-2
immunity in children with distinct symptomatology. METHODS: Between
March and July 2020, we recruited 15 SARS-CoV-2 asymptomatic (AS) and 51
symptomatic children (SY), stratified according to WHO clinical
classification. We measured SARS-CoV-2 viral load using ddPCR and qPCR
in longitudinally collected nasopharyngeal swabs samples. To define
anti-SARS-CoV-2 antibodies we measured neutralization activity and total
IgG load (Diasorin). We also evaluated antigen-specific B and
CD8+T-cells, using a labelled S1+S2 protein and ICAM expression,
respectively. Plasma protein profiling was performed with Olink.
RESULTS: Virological profiling showed that AS had lower viral load at
diagnosis (p=0.004) and faster virus clearance (p=0.0002) compared to
SY. Anti-SARS CoV-2 humoral and cellular response did not appear to be
associated with the presence of symptoms. AS and SY showed similar
titers of SARS-CoV-2 IgG, levels of neutralizing activity, and frequency
of Ag-specific B and CD8+T-cells. Whereas pro-inflammatory plasma
protein profile was associated to symptomatology. CONCLUSION: We
demonstrated the development of anti-SARS-CoV-2 humoral and cellular
response with any regards to symptomatology, suggesting the ability of
both SY and AS to contribute towards herd immunity. The virological
profiling of AS suggested that they have lower virus load associated
with faster virus clearance.