SARS-CoV-2 sero-immunity and quality of life in children and adolescents in relation to infections and vaccinations: the IMMUNEBRIDGE KIDS cross-sectional study, 2022
Authors: Engels Geraldine , Oechsle Anna-Lisa , Schlegtendal Anne , Maier Christoph , Holzwarth Sarah , Streng Andrea , Lange Berit , Karch Andre , Petersmann Astrid , Streeck Hendrik , Blaschke-Steinbrecher Sabine , Härtel Christoph , Schroten Horst , von Kries Rüdiger , Berner Reinhard , Liese Johannes , Brinkmann Folke , Toepfner Nicole ,   the IMMUNEBRIDGE KIDS study group, Forster Johannes , Kurzai Oliver , Pietsch Franziska , Hick Elena , Hecker Katharina , Lücke Thomas , Hoffmann Anna , Schwarzbach Michaela , Höppner Jakob , Drinka Denisa , Armann Jakob , Blankenburg Judith , Falke Uta , Schneider Josephine , Jäger Veronika , Rücker Viktoria , Harries Manuela , Hassenstein Max , Dreier Maren , von Holt Isabell , Budde Axel , Kurosinski Marc-André , Bartz Antonia , Brandhorst Gunnar , Brinkmann Melanie , Budde Kathrin , Deckena Marek , Fenzlaff Marc , Hovardovska Olga , Kehl Katja , Kohls Mirjam , Krüger Stefan , Meyer-Schlinkmann Kristin , Ottensmeyer Patrick , Reese Jens-Peter , Rosenkranz Daniel , Rübsamen Nicole , Schattschneider Mario , Schäfer Christin , Schlinkert Simon , Schulze-Wundling Kai , Störk Stefan , Tiemann Carsten , Völzke Henry , Winter Theresa , Heuschmann Peter , Nauck Matthias 
Published: June 2023

Abstract
Purpose
The study evaluates the effects on sero-immunity, health status and quality of life of children and adolescents after the upsurge of the Omicron variant in Germany.

Methods
This multicenter cross-sectional study (IMMUNEBRIDGE Kids) was conducted within the German Network University Medicine (NUM) from July to October 2022. SARS-CoV-2- antibodies were measured and data on SARS-CoV-2 infections, vaccinations, health and socioeconomic factors as well as caregiver-reported evaluation on their children’s health and psychological status were assessed.

Results
497 children aged 2–17 years were included. Three groups were analyzed: 183 pre-schoolchildren aged 2–4 years, 176 schoolchildren aged 5–11 years and 138 adolescents aged 12–18 years. Positive antibodies against the S- or N-antigen of SARS-CoV-2 were detected in 86.5% of all participants (70.0% [128/183] of pre-schoolchildren, 94.3% of schoolchildren [166/176] and 98.6% of adolescents [136/138]). Among all children, 40.4% (201/497) were vaccinated against COVID-19 (pre-schoolchildren 4.4% [8/183], schoolchildren 44.3% [78/176] and adolescents 83.3% [115/138]). SARS-CoV-2 seroprevalence was lowest in pre-school. Health status and quality of life reported by the parents were very positive at the time of the survey (Summer 2022).

Conclusion
Age-related differences on SARS-CoV-2 sero-immunity could mainly be explained by differences in vaccination rates based on the official German vaccination recommendations as well as differences in SARS-CoV-2 infection rates in the different age groups. Health status and quality of life of almost all children were very good independent of SARS-CoV-2 infection and/or vaccination.

Trial registration
German Registry for Clinical Trials Identifier Würzburg: DRKS00025546 (registration: 11.09.2021), Bochum: DRKS00022434 (registration:07.08.2020), Dresden: DRKS 00022455 (registration: 23.07.2020).