evidence: The Phase 1/2 clinical trial is double-blind and placebo-controlled study to evaluate safety, tolerability and immunogenicity of two doses of the vaccine. 60 adults are enrolled in the trial. For more information about this clinical trial, please refer to jRCT No.:2031210269. Subject registration for this trial has been completed. In the evaluation up to 28 days of two doses of the vaccine, confirmed tolerability and safety, neutralizing antibody titer equal to or higher than that of convalescent serum. [...] This clinical trial is a randomized, active controlled, double-blind trial. In this trial, the efficacy and safety of an additional dose of COMIRNATY or S-268019 in 200 adults, 6 months or more after receiving a primary series of COMIRNATY, will be compared. For more information about this clinical trial, please refer to jRCT No.:2031210470. Subject registration for this trial has been completed and the primary endpoint was achieved for the neutralizing antibody titer against SARS-CoV-2 28 days after additional dose. [...] This clinical trial is a double-blind randomized active controlled trial to evaluate a neutralizing antibody titer after the primary series of Vaxzevria or S-268019 in 1,000 adults and the elderly people.For more information about this clinical trial, please refer to jRCT No.: 2051210151.