Cuban vaccines against COVID-19 prove to be safe, effective, and capable of controlling the epidemic

Havana, Dec 19 (RHC) Cuban vaccines against COVID-19 prove to be safe, effective, and capable of controlling the epidemic, and the process of recognition by the World Health Organization (WHO) is advancing according to established procedures, informed the president of the BioCubaFarma business group, Eduardo Martínez Díaz.

In statements to Granma newspaper, Martínez Díaz said that information on the Abdala vaccine dossier has been sent and is being exchanged with the authorities of the international organization.

However, the executive said that one aspect of the evaluation process has a delay since it depends on the visit of WHO experts to the plants where the vaccines are manufactured.

The inspection had been planned for the end of this year at the production facilities of the CIGB-Mariel biotechnological complex, where the production of the Abdala vaccine is being transferred, but the line that manufactures the recombinant products has been delayed in its start-up.

For nine months, Cuba has been trying to make payments to the company in charge of starting up the equipment and systems of that production line, although it has not been possible due to the refusal of several banks to make the transfer operation, said Martínez Díaz.

Despite these difficulties, progress is being made: the production line is already active and producing, he said.

We hope that in 2023 the WHO evaluation process will be completed, he said.

According to the specialist, Cuban vaccines have several characteristics that distinguish them from others that have been developed, due to their safety, high thermo-stability, and effectiveness.

Their results have been reviewed by international experts, in a peer review process, and to date, more than 20 scientific articles have been published in high-impact journals and other reports continue to be prepared, said the president of BioCubaFarma.

Likewise, Cuban immunogens have been evaluated by the regulatory authorities of several countries, which have finally granted the Emergency Use Authorization.  He detailed that at the moment eight countries have given this authorization and others are evaluating them.

As another sign of the international recognition of the vaccines developed in Cuba, the executive mentioned the recent visit of experts and scientists from prestigious institutions in the United States, the Caribbean, and Africa, who had access to all the information available on the results obtained.

Regarding the characteristics of the Cuban anti-COVID-19 vaccines, the executive said that after tens of millions of doses applied in the Antillean nation and other countries, the adverse events are mild and with very low frequency, even in the pediatric population from two to 18 years of age, a unique experience in the world to date.

These are not coincidental results, he said; the very nature of the technological platforms used and the design of the vaccines justify them.

He also pointed out that, unlike other vaccines that require special conditions for their storage, at freezing temperatures, Cuban vaccines can be stored between two and eight degrees Celsius.

It has even been demonstrated that they maintain their quality characteristics at temperatures above 30 degrees Celsius for at least a week, which makes them attractive for use in poor countries, where there are difficulties in maintaining the cold chain, he said.

He added that the clinical studies carried out showed efficacy of more than 90 percent, but the most important evidence of effectiveness was the impact achieved in the reduction of the transmission of the disease in Cuba, as of October 2021, when 60 % of the population was immunized, using Abdala and Soberana vaccines.

He also stated that Cuban vaccines have proven to be effective against omicron, and proof of this is that in the country the peak of infections with this variant and its subvariants has been lower than the previous ones, including the peak with delta.

Undoubtedly, the effectiveness of the vaccines created by Cuban scientists against these new strains of SARS-COV-2 (the virus causing COVID-19), and the immunization strategy have a lot to do with this behavior on the island, said Martínez Díaz.

He added that laboratory studies carried out in Cuba and other countries have found that the antibodies induced by Cuban vaccines neutralize the omicron variant (the most infectious of COVID-19 known so far).

While some vaccines report a decrease of up to 20 times in the capacity to neutralize the omicron variant of SARS-COV-2, concerning the original, the Cuban vaccines only decrease this neutralization capacity by two times.

Abdala and Soberana use the RBD antigen (the region of the spike protein that binds to the virus receptor in the cell), which induces neutralizing antibodies against a preserved region of the protein among the different variants of the virus, possibly because of the importance of this region in the functionality of the virus; therefore, mutations in this area of the protein are not selected, he explained.

When immunized with the complete spike (S) protein, this preserved region is not immunodominant, for instance, antibodies are induced preferentially against other areas of the protein, in which there is a high rate of mutations, and a process of selection of the variants that escape recognition by neutralizing antibodies takes place.

He specified that most of the vaccines currently on the market use the spike (S) protein as an antigen, which has generated the phenomenon of successive pandemic peaks as a result of the appearance of virus variants that escape the immunity generated by these vaccines.

We defend the hypothesis that the vaccines based on the RBD antigen can constitute a universal reinforcement for the rest of the vaccines against COVID-19, amplifying a protective immunity against the different variants of the SARS-COV-2 virus, which have circulated or which could be generated in the future, he said, and added that recently several groups of scientists in the world have published articles supporting this hypothesis. (Source: Granma)