The SARS-coronavirus (SARS-CoV) is the viral pathogen causing severe acute respiratory syndrome (SARS). There are no vaccines available yet that can protect against the virus. Several lines of evidence suggest that the virus establishes its infection via mucosal routes. Production of oral vaccines to induce specific mucosal antibody response will therefore represent the most effective approach to preventing SARS infection. In this study, a synthetic gene encoding an antigenic region of the SARS-CoV Spike protein that induces neutralizing antibodies was fused with a bacterial gene coding for cholera toxin B subunit (CTB), a mucosal carrier molecule for the efficient generation of mucosal antibody responses to linked antigens. The CTB-Spike (CTB-S) chimeric gene was under the control of the double CaMV 35S promoter. Agrobacterium-mediated transformation was used to introduce the chimeric gene into tobacco plants. PCR analysis confirmed the presence of the CTB-S genes in the transgenic plants. The expression of the CTB-S gene in the transgenic plants was demonstrated by northern blot hybridization and western blot analysis. GM1 binding ELISA assay showed that the CTB-S fusion protein efficiently binds to the mucosal GM1 receptor. The availability of transgenic plants expressing CTB-S provides a solid foundation for the development of a plant-based, safe, cost-effective, edible vaccine against SARS.