Antibody responses to SARS-CoV2 are distinct in children with MIS-C compared to adults with COVID-19

Area of Science:

• Immunology
• Virology
• Pediatrics

Background:

• COVID-19 clinical presentation varies significantly with age.
• Children can develop SARS-CoV-2-associated multisystem inflammatory syndrome (MIS-C), resembling Kawasaki disease, despite generally milder respiratory illness.
• Understanding age-specific immune responses is crucial for targeted treatments.

Approach:

• Compared antibody profiles in children with MIS-C to adults with severe COVID-19 (ARDS) and recovered mild COVID-19 patients.
• Assessed antibody breadth, specificity (anti-Spike and anti-Nucleocapsid), and neutralizing activity.
• Analyzed IgG, IgM, and IgA antibody isotypes.

Key Points:

• Children with MIS-C exhibited a narrower range and lower specificity of anti-SARS-CoV-2 antibodies compared to adult COVID-19 patients.
• MIS-C patients predominantly produced IgG antibodies against the Spike (S) protein, unlike adult cohorts who also developed anti-Nucleocapsid (N) antibodies.
• Neutralizing antibody activity was significantly lower in MIS-C patients, suggesting a less protective serological response.

Conclusions:

• Distinct antibody response patterns differentiate pediatric MIS-C from adult COVID-19, including severe ARDS.
• The reduced antibody breadth, specificity, and neutralizing capacity in MIS-C indicate a unique SARS-CoV-2 infection course in children.
• Findings have implications for age-stratified treatment strategies and understanding pediatric immune responses to SARS-CoV-2.