Oral Vaccination Protects Against Severe Acute Respiratory Syndrome Coronavirus 2 in a Syrian Hamster Challenge Model

Background. Vaccines that are shelf stable and easy to administer are crucial to improve vaccine access and reduce severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission around the world. Methods. In this study, we demonstrate that an oral, adenovirus-based vaccine candidate protects against SARS-CoV-2 in a Syrian hamster challenge model. Results. Hamsters administered 2 doses of VXA-CoV2-1 showed a reduction in weight loss and lung pathology and had completely eliminated infectious virus 5 days postchallenge. Oral immunization induced antispike immunoglobulin G, and neutralizing antibodies were induced upon oral immunization with the sera, demonstrating neutralizing activity. Conclusions. Overall, these data demonstrate the ability of oral vaccine candidate VXA-CoV2-1 to provide protection against SARS-CoV-2 disease.