The clinical trial’s preliminary results show a significant increase in the immune responses of patients between the second and third doses.

On Thursday, Cuba’s Finlay Vaccine Institute announced that its Soberana 02 COVID-19 vaccine is most likely to reach up to 95 percent efficiency in third phase of clinical trials.

FVI scientist Maria Toledo explained that that Sovereign 02 research team opted for an application scheme with three doses because the immune response to the vaccine needed to be sustained over time.

She also pointed out that although the clinical trial has not yet concluded, its preliminary results show a significant increase in the immune responses of patients between the second and third doses.

“This yields an immunization schedule efficacy of between 85 and 95 percent”, Toledo said, adding that more experimental data could be available next week.

Besides Soberana 02, Cuba has developed four COVID-19 vaccines: Soberana 01 and Soberana Plus, which were also created by FVI, and Abdala and Mambisa, which were developed by the Center for Genetic Engineering and Biotechnology (CIGB).

All Cuban vaccines contain “a protein subunit” so they produce an immune response through the inoculation of a COVID-19 spike protein. In the IFV vaccines, the antigen was grown in mammalian cells. With the CIGB products, on the other hand, the spike protein was cultivated in yeasts.

Cuba’s Center for the Control of Medicines, Equipment and Medical Devices is currently evaluating Abdala prototype to get the official vaccine status. Health authorities’ purpose is to have 70 percent of the population vaccinated in September and 100 percent before the end of the year.