ABSTRACT
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 subjects made CD4+ T cell responses after one and two doses of NVX-CoV2373, and a subset of individuals made CD8+ T cell responses. Characterization of the vaccine-elicited CD8+T cells demonstrated IFNγ production. Characterization of the vaccine-elicited CD4+ T cells revealed both circulating T follicular helper cells (cTFH) and TH1 cells (IFNγ, TNFα, and IL-2) were detectable within 7 days of the primary immunization. Spike-specific CD4+ T cells were correlated with the magnitude of the later SARS-CoV-2 neutralizing antibody titers, indicating that robust generation of CD4+ T cells, capable of supporting humoral immune responses, may be a key characteristic of NVX-CoV2373 which utilizes Matrix-M™ adjuvant.
Competing Interest Statement
A.S. is a consultant for Gritstone, Flow Pharma, Merck, Epitogenesis, Gilead and Avalia. S.C. has consulted for GSK, Roche, Nutcracker Therapeutics, and Avalia. LJI has filed for patent protection for various aspects of T cell epitope and vaccine design work. C.K., N.F. J.P, M.Z., S. C-C, and A.G. are current or former employees of Novavax;and L.F. is a contractor to Novavax.