Durable immunity to SARS-CoV-2 in both lower and upper airways achieved with a gorilla adenovirus (GRAd) S-2P vaccine in non-human primates.

SARS-CoV-2 continues to pose a global threat, and current vaccines, while effective against severe illness, fall short in preventing transmission. To address this challenge, there's a need for vaccines that induce mucosal immunity and can rapidly control the virus. In this study, we demonstrate that a single immunization with a novel gorilla adenovirus-based vaccine (GRAd) carrying the pre-fusion stabilized Spike protein (S-2P) in non-human primates provided protective immunity for over one year against the BA.5 variant of SARS-CoV-2. A prime-boost regimen using GRAd followed by adjuvanted S-2P (GRAd+S-2P) accelerated viral clearance in both the lower and upper airways. GRAd delivered via aerosol (GRAd(AE)+S-2P) modestly improved protection compared to its matched intramuscular regimen, but showed dramatically superior boosting by mRNA and, importantly, total virus clearance in the upper airway by day 4 post infection. GrAd vaccination regimens elicited robust and durable systemic and mucosal antibody responses to multiple SARS-CoV-2 variants, but only GRAd(AE)+S-2P generated long-lasting T cell responses in the lung. This research underscores the flexibility of the GRAd vaccine platform to provide durable immunity against SARS-CoV-2 in both the lower and upper airways.
Competing Interests: Declaration of interests M.R., N.J.S., and D.C.D. are inventors on U.S. Patent Application No. 63/147,419 entitled “Antibodies Targeting the Spike Protein of Coronaviruses”. L.P., A.V.R., D.V., A.C., A.D., M.G.L., and H.A. are employees of Bioqual, Inc. A.L., A.V., S.Co., A.F., A.R., and S.Ca. are employees of ReiThera Srl. S.Co. and A.F. are shareholders of Keires AG. A.V., S.Co. and A.R. are named inventors of the Patent Application No. 20183515.4 entitled “Gorilla Adenovirus Nucleic Acid- and Amino Acid-Sequences, Vectors Containing Same, and Uses Thereof”. The other authors declare no competing interests.