Search

Plant-based edible vaccines that provide two-layered protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outweigh the currently used parenteral types of vaccines, which predominantly cause a systemic immune response. Here, we engineered and selected a transgenic tomato genotype (TOMAVAC) that stably synthesized an antigenic S1 protein of SARS-CoV-2. Two-course spaced force-feeding of mice with ≈5.4 μg/ml TOMAVAC increased up to 16-fold the synthesis of RBD-specific NAbs in blood serum and the significant induction of S-IgA in intestinal lavage fluid. In a surrogate virus neutralization test, TOMAVAC-induced NAbs had 15-25% viral neutralizing activity. The results suggested early evidence of the immunogenicity and protectivity of TOMAVAC against the coronavirus disease 2019 (COVID-19) infection. Furthermore, we observed a positive trend of statistically significant 1.2-fold (average of +42.28 BAU/ml) weekly increase in NAbs in the volunteers' serum relative to the initial day. No severe side effects were observed, preliminarily supporting the safety of TOMAVAC. With the completion of future large-scale studies, higher-generation TOMAVAC should be a cost-effective, ecologically friendly, and widely applicable novel-generation COVID-19 vaccine, providing two-layered protection against SARS-CoV-2., Competing Interests: The study concept and results have been filed for patenting at the Intellectual Property Agency under the Ministry of Justice of the Republic of Uzbekistan with pending application no. IAP 2022 0247., (Copyright © 2024 Buriev, Shermatov, Usmanov, Mirzakhmedov, Ubaydullaeva, Kamburova, Rakhmanov, Ayubov, Abdullaev, Eshmurzaev, Mamajonov, Tulanov, Ismailova, Petrova, Rozumbetov, Aripova, Muminov, Ermatova, Dalimova, Turdikulova, Abdukarimov and Abdurakhmonov.)