How is the international recognition, and the evaluation by WHO, of Cuban vaccines against COVID-19 going?
Clinical studies showed the Cuban vaccines against COVID-19 have over 90% efficacy.
By Liz Conde Sánchez | internet@granma.cu
The sustained control of the incidence of the disease on the Island is a reliable proof of this. Another one is the growing international recognition obtained by Cuban vaccines, regardless of the progress of the recognition process by the World Health Organization (WHO).
In an interview, with Dr. Eduardo Martínez Díaz, president of the BioCubaFarma business group, he listed the characteristics that make Cuban vaccines stand out, the evidence that proves their effectiveness, the international recognition they have obtained, and the evaluation process by the WHO.
- What are the characteristics that distinguish Cuban vaccines against COVID-19?
- Cuban vaccines against COVID-19 have several characteristics that make them stand out among others that have been developed.
"First, they have proven to be very safe. After dozens of millions of doses applied, in Cuba and in other countries, it has been observed that adverse events are mild and with a very low frequency, even in pediatric population from two to 18 years old, which is a unique experience in the world to date.
"These are not casual results; the very nature of the technological platforms used and the design of the vaccines justify them.
"Secondly, these vaccines have high thermo-stability. Unlike others that require special conditions for storage, at freezing temperatures, ours can be stored between 2 and 8 degrees Celsius.
"They have even been shown to maintain their quality characteristics at temperatures above 30 Celsius degrees for at least a week, making them attractive for use in poor countries where there are difficulties in maintaining the immunogen's cold chain.
"Thirdly, Cuban vaccines have proven to be very effective.
"In the clinical studies carried out, they have proven to have an efficacy of over 90 %. However, the most important evidence of their effectiveness was the decrease in the transmission of the disease in Cuba, starting October 2021, when the population have been immunized in 60% using Abdala and Soberana vaccines."
- How effective have Cuban vaccines proven to be against the Omicron variant?
- Cuban vaccines have proven to be effective against the Omicron variant, the most infectious variant of this disease known so far.
"Epidemiological evidence proves it. In Cuba, unlike most countries in the world, the peak of infections with the Omicron variant and its subvariants have been lower when compared to the previous ones, including the peak with Delta.
"Undoubtedly, the effectiveness of the vaccines created by our scientists against these new SARS-COV-2 strains and the vaccination strategy have a lot to do with this behavior on the island.
"We have found, in laboratory studies done in Cuba and in other nations, that the antibodies induced by Cuban vaccines neutralize the Omicron variant. While some vaccines report a decrease of up to 20 times in their capacity to neutralize the Omicron variant of SARS-COV-2, compared to the original, Cuban vaccines only decrease this neutralization capacity by two times.
"This phenomenon we are observing has its explanation in the nature of the antigen we use and the very design of our vaccines.
"The Abdala and Soberana vaccines use the RBD antigen, that is, the spike (S) protein region, which binds to the virus receptor in the cell.
"The RBD antigen has been found to induce neutralizing antibodies against a conserved region of that protein among the different variants of the virus, possibly because of the importance of that region in the functionality of the virus; therefore, mutations in this area of the protein are not selected.
"However, when immunized with the complete spike (S) protein, this conserved region is not immunodominant, in other words, antibodies are preferentially induced against other areas of the protein, in which there is a high rate of mutations, and a process of selection of variants that escape recognition by neutralizing antibodies occurs.
"Most of the vaccines currently on the market use the spike (S) protein as antigen, which has generated the phenomenon of successive pandemic peaks resulting from the appearance of variants of the virus that escape the immunity generated by these vaccines.
"We defend the hypothesis that vaccines based on the RBD antigen may constitute a universal booster 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 could appear in the future.
"Recently, several groups of scientists around the world have published papers supporting this hypothesis."
- How is the international recognition of Cuban vaccines advancing?
- All these results have been published in recognized scientific journals, which means, they have been reviewed by international experts, in a peer review process.
"To date, more than 20 scientific articles have been published in high-impact journals and other reports are being prepared.
"Cuban vaccines have also been evaluated by regulatory authorities in several countries, which have finally granted the Emergency Use Authorization.
"Eight countries have given this authorization so far and others are evaluating them.
"Not so long ago, a group of experts and scientists from prestigious institutions in the United States, the Caribbean and Africa visited our country and had access to all the information available on the results obtained, held meetings with specialists, doctors, scientists and technologists, both in health institutions and in biotechnological facilities, recognizing the work done and the quality of Cuban vaccines, and issued a public report".
- How is the process of evaluation and recognition of Cuban vaccines by the WHO going?
-The WHO recognition process started this year, and several steps have been taken in line with the established procedures.
"Information from the Abdala vaccine dossier has been sent and is being exchanged with those authorities.
"However, one of the components of the evaluation process is behind schedule.
-The delay is due to the visit of WHO experts to the plants where the vaccines are manufactured.
"We had prepared this visit to take place at the end of the year at the production facilities of the CIGB-Mariel biotechnology complex, where the production of the Abdala vaccine is being transferred.
"Although the production line, in which the formulation, filling and packaging operations of that complex are already active and producing, the line in which the recombinant products are manufactured has delays in its start-up.
"This delay is given because it has not been possible to make the payments to the company in charge of the start-up of the equipment and systems of that production line.
"We have been trying for nine months to make the payments, which have not been possible due to the refusal of several banks to make the transfer operation.
"Notwithstanding these difficulties, we’ve made progress and we hope that the WHO evaluation process will be completed in 2023."
Translated by ESTI
