A Gamma-adapted subunit vaccine induces broadly neutralizing antibodies against SARS-CoV-2 variants and protects mice from infection

CORIA, L.M.; RODRIGUEZ, J.M.; DEMARIA, A.; BRUNO, L.A.; MEDRANO, M.R.; CASTRO, C.P.; CASTRO, E.F.; DEL PRIORE, S. A.; INSUA, A.C.H.; KAUFMANN, I.G.; SAPOSNIK, L.M.; STONE, W.B.; PRADO, L.; NOTARO, U.; AMWEG, A.; DÍAZ, P.; AVARO, M.; ORTEGA, H.; CEBALLOS, A.; KRUM, V.; ZURVARRA, F.M.; SIDABRA, J.E.; DREHE, I.; BAQUÉ, J.A.; CAUSI, M.L.; DE NICHILO, A.V.; PAYES, C.J.; SOUTHARD, T.; VEGA, J.C.; AUGUSTE, A.J.; ÁLVAREZ, D.E.; FLO, J.M.; PASQUEVICH, K.A.; CASSATARO, J.

NATURE COMMUNICATIONS

nature

Año: 2024 vol. 15

2041-1723

In the context of continuous emergence of SARS-CoV-2 variants of concern(VOCs), one strategy to prevent the severe outcomes ofCOVID-19 is developingsafe and effective broad-spectrum vaccines. Here, we present preclinical studiesof a RBD vaccine derived from the Gamma SARS-CoV-2 variant adjuvantedwith Alum. The Gamma-adapted RBD vaccine is more immunogenic than theAncestral RBD vaccine in terms of inducing broader neutralizing antibodies.The Gamma RBD presents more immunogenic B-cell restricted epitopes andinduces a higher proportion of specific-B cells and plasmablasts than theAncestral RBD version. The Gamma-adapted vaccine induces antigen specific Tcell immune responses and confers protection against Ancestral and OmicronBA.5 SARS-CoV-2 challenge in mice. Moreover, the Gamma RBD vaccine induceshigher and broader neutralizing antibody activity than homologous boostervaccination in mice previously primed with different SARS-CoV-2 vaccineplatforms. Our study indicates that the adjuvanted Gamma RBD vaccine ishighly immunogenic and a broad-spectrum vaccine candidate.