PT  - JOURNAL ARTICLE
AU  - Ricardo Choque-Guevara
AU  - Astrid Poma-Acevedo
AU  - Ricardo Montesinos-Millán
AU  - Dora Rios-Matos
AU  - Kristel Gutiérrez-Manchay
AU  - Angela Montalvan
AU  - Stefany Quiñones-Garcia
AU  - Maria de Grecia Cauti-Mendoza
AU  - Andres Agurto-Arteaga
AU  - Ingrid Ramirez-Ortiz
AU  - Manuel Criollo-Orozco
AU  - Edison Huaccachi-Gonzales
AU  - Yomara K. Romero Lázaro
AU  - Norma Perez-Martinez
AU  - Gisela Isasi-Rivas
AU  - Yacory Sernaque-Aguilar
AU  - Doris Villanueva-Pérez
AU  - Katherine Vallejos-Sánchez
AU  - Manolo Fernández-Sánchez
AU  - Luis Guevara
AU  - Manolo Fernández-Díaz
AU  - Mirko Zimic
AU  - for the COVID-19 Working Group in Perú
TI  - A recombinant SARS-CoV-2 RBD antigen expressed in insect cells elicits immunogenicity and confirms safety in animal models
AID  - 10.1101/2021.11.26.470043
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.11.26.470043
4099  - http://biorxiv.org/content/early/2021/11/30/2021.11.26.470043.short
4100  - http://biorxiv.org/content/early/2021/11/30/2021.11.26.470043.full
AB  - COVID-19 pandemic has accelerated the development of vaccines against its etiologic agent, SARS-CoV-2. However, the emergence of new variants of the virus requires new immunization strategies in addition to the current vaccines approved for human administration. In the present report, the immunological and safety evaluation in mice and hamsters of a subunit vaccine based on the RBD sub-domain with two adjuvants of oil origin is described.The RBD protein was expressed in insect cells and purified by chromatography until >95% purity. The protein was shown to have the appropriate folding as determined by ELISA and flow cytometry binding assays to its receptor, as well as by its detection by hamster immune anti-S1 sera under non-reducing conditions.In immunization assays in mice and hamsters, the purified RBD formulated with adjuvants based on oil-water emulsifications and squalene was able to stimulate specific neutralizing antibodies and confirm the secretion of IFN-γ after stimulating spleen cells with the purified RBD. The vaccine candidate was shown to be safe, as demonstrated by the histopathological analysis in lungs, liver and kidney. These results demonstrate the potential of the purified RBD administered with adjuvants through an intramuscular route, to be evaluated in a challenge against SARS-CoV-2 and determine its ability to confer protection against infection.Competing Interest StatementThe authors have declared no competing interest.