Sovereign 2: Clinical Trials Coming Soon

Interview with Dr. Vicente Vérez Bencomo, director of the Finlay Institute, discussing the new COVID-19 candidate vaccine, Soberana 2, unlike any other under development around the world

Author: Orfilio Peláez | informacion@granmai.cu

October 23, 2020 14:10:39

Photo: twitter@FinlayInstituto Photo: Granma

Cuban science will reach another milestone in the battle against COVID-19 when authorization to conduct clinical evaluation of a second candidate vaccine against the disease is granted by the Center for the State Control of Drugs, Equipment and Medical Devices (Cecmed).

Doctor of Science Vicente Vérez Bencomo, general director of the Finlay Vaccine Institute, affiliated with the BioCubaFarma Enterprise Group, stated in an interview with Granma that the new candidate, given the name of Soberana 2, is an innovative vaccine, unlike any other under development to confront the COVID-19 pandemic around the world.

Its novelty consists in being a conjugated vaccine, in which the antigen of the virus, the receptor binding domain (RBD), is chemically linked to a tetanus toxoid, he explained.

-When you mention the virus antigen, does this mean that it is used in the new vaccine candidate?

-No, both Soberana 1 and Soberana 2 are molecular vaccines or subunit vaccines.

This means that the vaccine antigen is a molecule which is a copy of the molecule present in the virus. To obtain it, the viral protein’s genetic information must be known, and using a genetic engineering process, this data is programmed into a cell from a higher organism known as CHO.

In this way, we are able to express the viral protein in a cell, which in this case constitutes the 'factory' for producing the viral antigen.

The re-programmed CHO cell produces copies of the virus molecule, which is extracted and purified at the Molecular Immunology Center (CIM).

The thinking behind the two Sovereign vaccines is that the viral protein, which constitutes the vaccine antigen, is the same molecule. The two vaccines share a common process to obtain the viral antigen, and the difference lies in what is done subsequently.

-Have conjugated vaccines been developed before in Cuba or the world?

-This type of vaccine has been used, above all, in the prevention of bacterial infectious diseases.

The first conjugated vaccine developed worldwide was against Haemophilusinfluenzae type b or Hib, a bacterium that causes pneumonia and infant meningitis.

Cuba completed development of our vaccine against Hiben and registered it in 2004, when it was included in the National Vaccination Program.

In ours, the Hib antigen was fabricated entirely via chemical synthesis, which has remained a one-of-a-kind, world scientific novelty to date. Today, it is included in Cuba’s pentavalent vaccine, of which more than 40 million doses have been produced for use not only in Cuba, but in other countries, as well.

We have another conjugated vaccine in the development phase at the Finlay Vaccine Institute, which, in this case, is against pneumococci (the bacteria that causes pneumonia and infantile meningitis). Clinical trials in children from 1 to 5 years of age have already been completed, and the vaccine’s efficacy demonstrated. We are now working on productive scaling, in order to register it within a short period of time.

-What properties distinguish a conjugated vaccine, for example, from Sovereign 1?

-Known conjugated vaccines have two distinctive properties: they induce long term immunity and the antibodies generated not only offer protection against the disease, but also prevent the bacteria from colonizing the oropharynx of the person vaccinated. In case of a viral infection, such as COVID-19, we expect to find similar qualities.

-Can you tell us what is expected in the clinical trials of Sovereign 2?

-First, we expect to demonstrate that it is a safe vaccine, based on the record of other conjugated vaccines previously used, in addition to achieving a potent and long-lasting protective immune response, just like Sovereign 1.

Along with this, we expect that the immunity will reach the mucus membranes of the respiratory tract to prevent entry of the virus, and this will be the candidate vaccine we will propose to administer in the pediatric population.

This is a good moment to mention that all phases of research required in experimental animals for Sovereign 2 have been concluded, demonstrating a powerful and effective immune response against the virus. Based on these results, we have asked Cecmed for authorization to begin phase 1 clinical trials in healthy adults, and we expect to receive approval within a few days.

In addition to its safety, in the clinical trials we will determine which of the immunological properties we expect are confirmed in the vaccinated subjects.

-How much progress has been made with Soberana 1?

-As we have explained on other occasions, Soberana 1 is also a molecular vaccine, which contains the same virus molecule, in this case in a formula that contains two adjuvants, which serve to strongly stimulate the immune response.

The first two formulations reported on the Mesa Redonda (television program) in August, have continued successfully through the clinical trial. The two different doses were administered to participants in the study and it was possible to verify their safety, with very few adverse side effects, all of them mild.

Over the next few weeks, the phase 1 study will be completed with analysis of participants' immune response. We also expect a strong protective immune response from this vaccine that will last over time.

Additionally, we are rapidly developing three other formulas of the candidate vaccine, which began the phase 1 trial. This should allow us to select the best formulation in order to advance to subsequent phases of clinical trials.

Both candidate vaccines are based on technological platforms that have been used previously in Cuba and around the world, to prevent other infectious diseases.

It is worth noting that the clinical evaluation stage is not a formal stage, but the period established to assess and confirm in humans the desired protective response. It is the stage in which doses, treatment regimens, different age groups, and other aspects are evaluated.

Thus, timelines to achieve these results are required, which must be met to move through the different stages of clinical trials.

IN CONTEXT

-On July 28th, Soberana 1, the first Cuban, Latin American and Caribbean candidate vaccine against COVID-19, was tested for the first time in humans, an important achievement for Cuban science.

- “The vaccine’s name reflects patriotism and the revolutionary, humanist commitment with which the work has been done, and also responsibility to the foundational, and when we talk about foundational, we are talking about the Comandante en jefe," Cuban President Miguel Díaz-Canel stated last August, in a meeting with experts who have been directly involved in the COVID-19 battle.

-The vaccine has been achieved with prudence, with moderation, without boasting, the President noted, and warned, at that time, that more social responsibility was necessary to avoid a resurgence of COVID-19, and allow time to finalize the vaccine project in a better epidemiological situation.

-The results of the candidate vaccine’s clinical trials will be available next January, and scientists working on the project are making a great effort with a view toward beginning immunization of the population during the first six months of 2021.

-This accomplishment is the result of the coordinated work of the Finlay Vaccine Institute, the Molecular Immunology Center and the University of Havana’s Chemical and Biomolecular Synthesis Laboratory.

-The vaccine will provide the country technological sovereignty in the battle against COVID-19.

-The Finlay Vaccine Institute has more than 30 years of experience in the development of vaccines and a leader in the use of external membrane vesicle platforms (EMV).