%0 Journal Article
%T Evaluation of an RBD-nucleocapsid fusion protein as a booster candidate for COVID-19 vaccine.
%A Valiate BVS
%A Castro JT
%A Marçal TG
%A Andrade LAF
%A Oliveira LI
%A Maia GBF
%A Faustino LP
%A Hojo-Souza NS
%A Reis MAAD
%A Bagno FF
%A Salazar N
%A Teixeira SR
%A Almeida GG
%A Gazzinelli RT
%J iScience
%V 27
%N 7
%D 2024 Jul 19
%M 38993669
%F 6.107
%R 10.1016/j.isci.2024.110177
%X Despite successful vaccines and updates, constant mutations of SARS-CoV-2 makes necessary the search for new vaccines. We generated a chimeric protein that comprises the receptor-binding domain from spike and the nucleocapsid antigens (SpiN) from SARS-CoV-2. Once SpiN elicits a protective immune response in rodents, here we show that convalescent and previously vaccinated individuals respond to SpiN. CD4+ and CD8+ T cells from these individuals produced greater amounts of IFN-γ when stimulated with SpiN, compared to SARS-CoV-2 antigens. Also, B cells from these individuals were able to secrete antibodies that recognize SpiN. When administered as a boost dose in mice previously immunized with CoronaVac, ChAdOx1-S or BNT162b2, SpiN was able to induce a greater or equivalent immune response to homologous prime/boost. Our data reveal the ability of SpiN to induce cellular and humoral responses in vaccinated human donors, rendering it a promising candidate.