The hospital laboratory provided us the list of children under 15 years old tested for SARS-CoV-2 in Saint-Pierre Hospital (Brussels) by PCR on nasopharyngeal swab between March 1 2020 and December 31 2020.
The medical files of all children that were tested positive for SARS-CoV-2 were reviewed and clinical information was collected.
For each positive child, the family was contacted by phone 3 months after the proven viral infection in order to ask permission to take a single blood test.
Covid19 serologies were performed in the hospital laboratory, and blood samples were then sent to the Institute of Medical Immunology, were antibody levels and immunoglobulin subclasses were studied.
