Safety and Immunogenicity of a Recombinant Stabilized Prefusion SARS-CoV-2 Spike Protein Vaccine (MVC-COV1901) Adjuvanted With CpG 1018 and Aluminum Hydroxide in Healthy Adults: A Phase 1, Dose-Escalation Study

Background: This was a phase 1, dose-escalation open-label trial to evaluate the safety and immunogenicity of MVC-COV1901, SARS-CoV-2 S-2P protein vaccine adjuvanted with aluminum hydroxide CpG 1018. Methods: 45 healthy adults from 20 49 years age were be administered two vaccinations MVC-COV1901 in doses 5 μg, 15 or 25 μg spike at 28 days apart. There participants each dose group; all followed for after second vaccination time interim analysis. Adverse events (AEs) laboratory data recorded evaluation. Blood samples collected wild-type pseudovirus neutralization assays, spike-specific immunoglobulin G (IgG), cellular immune response various points. Findings: Solicited adverse mostly mild similar three groups. No subject experienced fever. After vaccination, serum neutralizing activity virus detected groups geometric mean values (76•3 [95% CI: 53•75 ~108•33], 167•4 122.05 ~229.61]) 1•8 3•9 times those panel control convalescent specimens (42•7, [95%CI: 26•38~69•04]). The induced by demonstrated substantially higher numbers IFN-γ- than IL-4- producing cells human peripheral blood mononuclear cells, suggesting Th1-skewed response. Interpretation: well tolerated elicited robust responses especially is suitable further development. Trial Registration: ClinicalTrials.gov NCT 04487210 Funding: Medigen Vaccine Biologics Corporation. Conflict Interest: Szu-Min Hsieh, Shan-Chwen Chang, Wang-Da Liu, Yu-Shan Huang declared that they have no knowncompeting financial interests personal relationships could appeared influence work reported this paper; Yi-Jiun Lin, Erh-Fang Wei-Cheng Lian, Charles Chen, I-Chen Tai are employee ofMedigen Corporation grants Taiwan Centers Disease Control, Ministry Health Welfare, during conduct study. In addition, Yi-Jiun. Lin Chen patent US63/040,696 pending. Robert Janssen an Dynavax Technologies Corporation. Ethical Approval: protocol informed consent form approved Food Drug Administration ethics committee site. conducted accordance principles Declaration Helsinki Good Clinical Practice. An independent monitoring board (DSMB) established monitor conduct.