High antibody levels and reduced cellular response in children up to one year after SARS-CoV-2 infection
Eva‐Maria Jacobsen, Dorit Fabricius, Magdalena Class, Fernando Topfstedt, Raquel Lorenzetti, Iga Janowska, Franziska Schmidt, Julian Staniek, Maria Zernickel, Thomas Stamminger, Andrea Dietz, Angela Zellmer, Manuel Hecht, Peter Rauch, Carmen Blum, Carolin Ludwig, Bernd Jahrsdörfer, Hubert Schrezenmeier, Maximilian Heeg, Benjamin Mayer, Alina Seidel, Rüdiger Groß, Jan Münch, Frank Kirchhoff, Sebastian F. N. Bode, Gudrun Strauß, Hanna Renk, Roland Elling, Maximillian Stich, Reinhard Voll, Burkhard Tönshof, Axel R. Franz, Philipp Henneke, Klaus‐Michael Debatin, Marta Rizzi, Aleš Janda
Abstract
The COVID-19 course and immunity differ in children and adults. We analyzed immune response dynamics in 28 families up to 12 months after mild or asymptomatic infection. Unlike adults, the initial response is plasmablast-driven in children. Four months after infection, children show an enhanced specific antibody response and lower but detectable spike 1 protein (S1)-specific B and T cell responses than their parents. While specific antibodies decline, neutralizing antibody activity and breadth increase in both groups. The frequencies of S1-specific B and T cell responses remain stable. However, in children, one year after infection, an increase in the S1-specific IgA class switch and the expression of CD27 on S1-specific B cells and T cell maturation are observed. These results, together with the enhanced neutralizing potential and breadth of the specific antibodies, suggest a progressive maturation of the S1-specific immune response. Hence, the immune response in children persists over 12 months but dynamically changes in quality, with progressive neutralizing, breadth, and memory maturation. This implies a benefit for booster vaccination in children to consolidate memory formation.