PT  - JOURNAL ARTICLE
AU  - Kuo, Tsun-Yung
AU  - Lien, Chia-En
AU  - Lin, Yi-Jiun
AU  - Lin, Meei-Yun
AU  - Wu, Chung-Chin
AU  - Tang, Wei-Hsuan
AU  - Campbell, John D.
AU  - Traquina, Paula
AU  - Chuang, Ya-Shan
AU  - Liu, Luke Tzu-Chi
AU  - Chen, Charles
TI  - Protection of Hamsters Challenged with SARS-CoV-2 Variants of Concern by Two Doses of MVC-COV1901 Vaccine Followed by a Single Dose of Beta Variant Version of MVC-COV1901
AID  - 10.1101/2021.09.29.462344
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.09.29.462344
4099  - http://biorxiv.org/content/early/2021/10/15/2021.09.29.462344.short
4100  - http://biorxiv.org/content/early/2021/10/15/2021.09.29.462344.full
AB  - The current fight against COVID-19 is compounded by the Variants of Concern (VoCs), which can diminish the effectiveness of vaccines and potentially increase viral transmission and severity of disease. MVC-COV1901 is a protein subunit vaccine based on the prefusion SARS-CoV-2 spike protein (S-2P) and is adjuvanted with CpG 1018 and aluminum hydroxide. In this study, we used the Delta variant to challenge hamsters inoculated with S-2P from the Wuhan wildtype and the Beta variant in two-dose or three-dose regimens. Two doses of wildtype S-2P followed by the third dose of Beta variant was shown to induce the highest neutralizing antibody titer against live SARS-CoV-2 of the wildtype as well as all current VoCs. All regimens of vaccination were able to protect hamsters from SARS-CoV-2 Delta variant challenge and resulted in reduced lung live virus titer and pathology. Three doses of vaccination also significantly reduced lung viral RNA titer, regardless of whether the wildtype or Beta variant S-2P was used as the third dose. Based on the immunogenicity and viral challenge data, two doses of wildtype S-2P followed by the third dose of Beta variant S-2P induced a broad and potent immune response against the Alpha, Beta, Gamma, and Delta variants.Competing Interest StatementC. C., T.-Y. K., C.-C. W., W.-.H. T, C.-E. L., Y.-J. L., and M.-Y. L. are co-inventors for US provisional patent applications 63/240,408, 63/240,080, and 63/248,189.