Assessing prevalence of SARS-CoV-2 infection in children by antibody detection in saliva: A prospective, longitudinal study protocol (Coro-Buddy).

Pinilla, Yudi T; Friessinger, Evelyn; Griesbaum, Johanna Marie; Berner, Lilith; Heinzel, Constanze; Elsner, Käthe; Fendel, Rolf; Held, Jana; Kreidenweiss, Andrea

BACKGROUND The world is confronting with the COVID-19 pandemic for more than one year. Severe disease is more often found in elderly people, whereas most of young children and adolescents show mild symptoms or even remain asymptomatic, so that infection might be undiagnosed. Therefore, only limited epidemiological data on SARS-CoV-2 infection in children and young adults are available. OBJECTIVE This study aims to determine the prevalence of SARS-CoV-2 antibodies in children from the city of Tübingen, Germany, and to follow the incidence of new cases in 12 months of follow-up. METHODS SARS-CoV-2 antibodies will be measured in saliva as a surrogate for a previous SARS-CoV-2 infection. Children will be sampled via (pre-schools, primary and secondary schools) at three time points: starting in German summer 2020, before winter and after winter 2021. An adult cohort will be sampled at the same time points (adult comparator group). The saliva-based SARS-CoV-2 antibody ELISA is validated with blood and saliva sampled from adults with confirmed previous SARS-CoV-2 infection (adult validation group). RESULTS Recruitment of participants to this study began in July 2020, and data collection will continue for a planned study period of 12 months. CONCLUSIONS Infection rates in children are commonly underreported due to lack of PCR testing. The study will inform about the prevalence of SARS-CoV-2 infections in infants, school children, adolescents and the incidence change over the upcoming 12 months (2020/2021) of the city of Tübingen, Germany. The saliva sampling approach for SARS-CoV-2 antibody measurement allows a unique and representative, population-based sample collection. CLINICALTRIAL Retrospectively registered at ClinicalTrials.gov: NCT04581889, 10 October, 2020. Acronym: Coro-buddy. INTERNATIONAL REGISTERED REPORT DERR1-10.2196/27739.