NVX-CoV2373 vaccination induces functional SARS-CoV-2-specific [CD4.sup.+] and [CD8.sup.+] T cell responses

NVX-CoV2373 is an adjuvanted recombinant full-length SARS-CoV-2 spike trimer protein vaccine demonstrated to be protective against COVID-19 in efficacy trials. Here we demonstrate that vaccinated individuals made [CD4.sup.+] T cell responses after 1 and 2 doses of NVX-CoV2373, and a subset of individuals made [CD8.sup.+] T cell responses. Characterization of the vaccine-elicited [CD8.sup.+] T cells demonstrated IFN-[gamma] production. Characterization of the vaccine-elicited [CD4.sup.+] T cells revealed both circulating T follicular helper (cTfh) cells and Th1 cells ([IFN-[gamma].sup.+], [TNF-[alpha].sup.+], and [IL-2.sup.+]) were detectable within 7 days of the primary immunization. Spike-specific [CD4.sup.+] T cells were correlated with the magnitude of the later SARS-CoV-2-neutralizing antibody titers, indicating that robust generation of [CD4.sup.+] T cells, capable of supporting humoral immune responses, may be a key characteristic of NVX-CoV2373 that utilizes Matrix-M adjuvant.