Immunogenicity and efficacy of recombinant subunit SARS-CoV-2 vaccine candidate in the Syrian hamster model

Balamurugan Shanmugaraj; Narach Khorattanakulchai; Weena Paungpin; Yada Akkhawattanangkul; Suwimon Manopwisedjaroen; Arunee Thitithanyanont; Waranyoo Phoolcharoen

doi:10.1016/j.btre.2022.e00779

Immunogenicity and efficacy of recombinant subunit SARS-CoV-2 vaccine candidate in the Syrian hamster model

Biotechnol Rep (Amst). 2023 Mar:37:e00779. doi: 10.1016/j.btre.2022.e00779. Epub 2022 Dec 13.

Authors

Balamurugan Shanmugaraj¹, Narach Khorattanakulchai^{2

3}, Weena Paungpin⁴, Yada Akkhawattanangkul⁴, Suwimon Manopwisedjaroen⁵, Arunee Thitithanyanont⁵, Waranyoo Phoolcharoen^{2

3}

Affiliations

¹ Baiya Phytopharm Co., Ltd, Bangkok, 10330, Thailand.
² Center of Excellence in Plant-produced Pharmaceuticals, Chulalongkorn University, Bangkok, 10330, Thailand.
³ Department of Pharmacognosy and Pharmaceutical Botany, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, 10330, Thailand.
⁴ Faculty of Veterinary Science, Mahidol University, Nakhon Pathom 73170, Thailand.
⁵ Department of Microbiology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.

Abstract

SARS-CoV-2 causes devastating impact on the human population and has become a major public health concern. The frequent emergence of SARS-CoV-2 variants of concern urges the development of safe and efficacious vaccine against SARS-CoV-2 variants. We developed a candidate vaccine Baiya SARS-CoV-2 Vax 1, based on SARS-CoV-2 receptor-binding domain (RBD) by fusing with the Fc region of human IgG. The RBD-Fc fusion was produced in Nicotiana benthamiana. Previously, we reported that this plant-produced vaccine is effective in inducing immune response in both mice and non-human primates. Here, the efficacy of our vaccine candidate was tested in Syrian hamster challenge model. Hamsters immunized with two intramuscular doses of Baiya SARS-CoV-2 Vax 1 induced neutralizing antibodies against SARS-CoV-2 and protected from SARS-CoV-2 challenge with reduced viral load in the lungs. These preliminary results demonstrate the ability of plant-produced subunit vaccine Baiya SARS-CoV-2 Vax 1 to provide protection against SARS-CoV-2 infection in hamsters.

Keywords: COVID-19; Plant-produced subunit vaccine; Protective immunity, Hamster challenge; Receptor binding domain; SARS-CoV-2.