Medigen Vaccine Biologics Corporation conducted the MVC COVID-19 Vaccine Phase 3 immuno-bridging clinical trial in Thailand, using AZ vaccine as a comparison vaccine to evaluate the immunogenic superiority. This trial design is based on the results of the consultation with the Stringent Regulatory Authority. It is characterized by including 40% elderly group (over 65 years old) of the total subjects, and to demonstrate the immunogenic superiority of MVC COVID-19 Vaccine in different ethnic groups.

The results showed good safety profile and immunogenic superiority of MVC COVID-19 Vaccine, which is similar to the results of the large-scale Phase 2 clinical trial conducted in Taiwan and Paraguay Phase 3 immuno-bridging trial. The results of this clinical trial are important supporting information to apply for the certification of the international pharmaceutical regulatory authorities. In the all subjects per protocol set, the neutralizing antibody titer produced by 2 doses of MVC COVID-19 Vaccine was 3.0 times higher than AZ Vaccine (95% CI: 2.0-4.5), and IgG binding antibodies was 4.7 times higher than AZ Vaccine (95% CI: 3.1-7.3); in elderly subjects, the neutralizing antibody titer was 2.8 times higher than AZ Vaccine (95% CI: 1.4-5.5), and the IgG binding antibodies was 3.4 times higher of AZ Vaccine (95% CI: 1.7-7.1).

In cellular immunity, administration of 2 doses MVC COVID-19 Vaccine induced TH1 cell immune bias in subjects of different age groups, regardless of whether they had been infected or not, and induced a good T cell immune response to the SARS-CoV-2.