Alberta Childhood COVID-19 Cohort (AB3C) [study data contributed to the CITF Databank]

Background: Given the novel SARS-CoV-2 coronavirus pandemic, there was a need to understand COVID-19 in Alberta children to inform potential treatments, vaccines, and public safety decisions such as when and how children should return to school. This study was not funded by the CITF; Dr. Kellner, as co-chair of the CITF Field Studies and Pediatric working groups, helped design the CITF Core Data Elements and questionnaires. Aims of the original study: The AB3C study aimed to determine how many children with and without known COVID-19 infections have made an immune response (blood antibodies) over time, and the epidemiologic and immunological correlates of infection risk and COVID disease severity. Methods: Parents were invited to enroll their child (less that 18 years) in the study if they lived in or near Calgary, AB. They were enrolled as single-visit or longitudinal participants. In addition to questionnaire items, at each visit (6 months apart) past COVID infection status was ascertained (priority to PCR result) and a blood sample drawn for serology. IgG antibodies to SARS-CoV-2 nucleocapsid protein and receptor binding domain of the spike were measured. Summary of the contributed data: The dataset includes 1030 participants who completed a baseline visit between August and November 2020 and provided at least one blood sample. 94% of participants were followed longitudinally up to 2 years (median: 19 months). Available variables include data for the following areas of information: demographics (age, sex, race-ethnicity and indigeneity, FSA), chronic health conditions, and BMI at baseline; acute COVID infection evidence, SARS-CoV-2 vaccination, and serology over time.