Immune responses to SARS-CoV-2 in three children of parents with symptomatic COVID-19

Nat Commun. 2020 Nov 11;11(1):5703. doi: 10.1038/s41467-020-19545-8.

Abstract

Compared to adults, children with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have predominantly mild or asymptomatic infections, but the underlying immunological differences remain unclear. Here, we describe clinical features, virology, longitudinal cellular, and cytokine immune profile, SARS-CoV-2-specific serology and salivary antibody responses in a family of two parents with PCR-confirmed symptomatic SARS-CoV-2 infection and their three children, who tested repeatedly SARS-CoV-2 PCR negative. Cellular immune profiles and cytokine responses of all children are similar to their parents at all timepoints. All family members have salivary anti-SARS-CoV-2 antibodies detected, predominantly IgA, that coincide with symptom resolution in 3 of 4 symptomatic members. Plasma from both parents and one child have IgG antibody against the S1 protein and virus-neutralizing activity detected. Using a systems serology approach, we demonstrate higher levels of SARS-CoV-2-specific antibody features of these family members compared to healthy controls. These data indicate that children can mount an immune response to SARS-CoV-2 without virological confirmation of infection, raising the possibility that immunity in children can prevent the establishment of SARS-CoV-2 infection. Relying on routine virological and serological testing may not identify exposed children, with implications for epidemiological and clinical studies across the life-span.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antibodies, Viral / blood*
  • Antibodies, Viral / immunology
  • Australia
  • Betacoronavirus / immunology*
  • CD4-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / immunology
  • COVID-19
  • Child
  • Child, Preschool
  • Coronavirus Infections / immunology
  • Coronavirus Infections / transmission*
  • Cytokines / blood*
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Humans
  • Immunoglobulin A / blood
  • Immunoglobulin A / immunology
  • Immunoglobulin G / blood
  • Immunoglobulin G / immunology
  • Male
  • Middle Aged
  • Monocytes / immunology
  • Pandemics
  • Parents
  • Pneumonia, Viral / immunology
  • Pneumonia, Viral / transmission*
  • SARS-CoV-2
  • Saliva / immunology*
  • Serologic Tests
  • Spike Glycoprotein, Coronavirus / immunology

Substances

  • Antibodies, Viral
  • Cytokines
  • Immunoglobulin A
  • Immunoglobulin G
  • Spike Glycoprotein, Coronavirus