Rapid and stable mobilization of CD8+ T cells by SARS-CoV-2 mRNA vaccine

Abstract SARS-CoV-2 spike mRNA vaccines 1–3 mediate protection from severe disease as early ten days after prime vaccination 3 , when neutralizing antibodies are hardly detectable 4–6 . Vaccine-induced CD8 + T cells may therefore be the main mediators of at this stage 7,8 The details their induction, comparison to natural infection, and association with other arms vaccine-induced immunity remain, however, incompletely understood. Here we show on a single-epitope level that stable fully functional cell response is vigorously mobilized one week bnt162b2, circulating CD4 still weakly detectable. Boost induced robust expansion generated highly differentiated effector cells; neither capacity nor memory precursor pool was affected. Compared exhibited similar capacities but different subset distribution. Our results indicate important cells, expanded in window vaccination, precede maturation stably maintained boost vaccination.