Bacillus Calmette-Guérin as adjuvant platform enhances immunogenicity of conserved epitopes from structural proteins of SARS-CoV-2

To validate conserved SARS-CoV-2 epitopes in combination with Bacillus Calmette-Guérin (BCG) and to design multiepitope vaccine constructs in silico.

In vitro assays: Dot blot assays confirmed recognition of five synthetic peptides by sera from convalescent patients. BCG–peptide formulations activated the MAPK pathway and induced trained immunity signatures in macrophages.
In vivo studies: Immunized mice showed modulation of IgG subclasses and increased production of IL-6, TNF-α, and IFN-γ. Splenocytes from vaccinated animals secreted high cytokine levels upon restimulation.
In silico modeling: Indicated stable, antigenic, and non-allergenic multiepitope constructs with favorable immune simulations.

Five synthetic peptides from SARS-CoV-2 structural proteins were recognized by convalescent sera.
BCG–peptide formulations activated immune pathways and induced trained immunity in macrophages.
Immunized mice exhibited enhanced IgG subclass modulation and increased cytokine production.
In silico models predicted effective multiepitope constructs.

The study primarily focuses on animal models, which may not fully replicate human responses.
In silico predictions require further validation through experimental studies.