Antibody Persistence After Primary SARS-CoV-2 Infection and Protection Against Future Variants Including Omicron in...

Area of Science:

• Immunology
• Virology
• Epidemiology

Background:

• Antibodies indicate immunity post-SARS-CoV-2 infection and may offer protection against reinfection and variants.
• Limited data exists on antibody persistence and cross-reactivity to SARS-CoV-2 variants after primary infection in children.

Purpose of the Study:

• To assess antibody persistence and cross-reactivity against SARS-CoV-2 variants after primary infection in a school setting.
• To compare antibody responses between students and staff.

Main Methods:

• Enhanced surveillance in 18 secondary schools to monitor SARS-CoV-2 infection.
• Longitudinal blood samples collected from students and staff for variant-specific antibody testing using in-house receptor binding domain assays.
• Analysis of 160 participants (97 students, 63 staff) positive for SARS-CoV-2 nucleocapsid antibodies at baseline.

Main Results:

• High rates of sustained antibodies against the wild-type (WT) strain were observed.
• Cross-reactive antibodies against Alpha, Beta, and Delta variants were detected, but at lower titers than WT.
• Significantly lower antibody titers against WT and variants were found in staff compared to students.
• Cross-reactive antibodies against the Omicron variant were rare (2.3% students, 17.2% staff).

Conclusions:

• Primary SARS-CoV-2 (COVID-19) infection leads to persistent antibodies and cross-protection against Alpha, Beta, and Delta variants.
• Wild-type infection does not appear to confer cross-protection against the Omicron variant.
• Differences in antibody responses between students and staff warrant further investigation.