Cutting Edge: Serum but Not Mucosal Antibody Responses Are Associated with Pre-Existing SARS-CoV-2 Spike Cross-Reactive CD4+ T Cells following BNT162b2 Vaccination in the Elderly
Lil Meyer‐Arndt, Tatjana Schwarz, Lucie Loyal, Larissa Henze, Beate Kruse, Manuela Dingeldey, Kübrah Gürcan, Zehra Uyar‐Aydin, Marcel A. Müller, Christian Drosten, Friedemann Paul, Leif Erik Sander, Ilja Demuth, Roland Lauster, Claudia Giesecke‐Thiel, Julian Braun, Victor M. Corman, Andreas Thiel
Abstract
Abstract Advanced age is a main risk factor for severe COVID-19. However, low vaccination efficacy and accelerated waning immunity have been reported in this age group. To elucidate age-related differences in immunogenicity, we analyzed human cellular, serological, and salivary SARS-CoV-2 spike glycoprotein-specific immune responses to the BNT162b2 COVID-19 vaccine in old (69–92 y) and middle-aged (24–57 y) vaccinees compared with natural infection (COVID-19 convalescents, 21–55 y of age). Serological humoral responses to vaccination excee-ded those of convalescents, but salivary anti-spike subunit 1 (S1) IgA and neutralizing capacity were less durable in vaccinees. In old vaccinees, we observed that pre-existing spike-specific CD4+ T cells are associated with efficient induction of anti-S1 IgG and neutralizing capacity in serum but not saliva. Our results suggest pre-existing SARS-CoV-2 cross-reactive CD4+ T cells as a predictor of an efficient COVID-19 vaccine-induced humoral immune response in old individuals.