More than a year after mass vaccination against COVID-19 began in our country, Cuban anti-pandemic vaccines continue to prove safe, effective and able to control the epidemic, even against the new highly contagious variants of the virus that exist appeared. in the world.
Reliable evidence of this is the sustained control of disease activity on the island and the growing international recognition that Cuban vaccines have received, regardless of the progress of the World Health Organization (WHO) recognition process.
In an interview, Dr. Eduardo Martínez Díaz, President of the BioCubaFarma Group, on the characteristics that distinguish Cuban vaccines, the evidence that proves their effectiveness, the international recognition they have received and the evaluation process carried out by The OMS.
– What are the characteristics of Cuban anti-COVID-19 vaccines?
– Cuban vaccines against COVID-19 have several characteristics that distinguish them from others that have been developed.
“First, they have proven to be very safe. After tens of millions of doses applied in Cuba and other countries, it has been observed that the side effects are mild and occur with very low frequency even in children aged two to 18 years, an experience unique in the world to date. .
“These are not random results, the nature of the technological platforms used and the design of the vaccines justify them.
Second, these vaccines have high thermostability. Unlike others that require special conditions for storage, ours can be stored at freezing temperatures between 2 and 8 degrees Celsius.
“They have been shown to retain their quality characteristics for at least a week even at temperatures above 30º Celsius, making them attractive for use in poor countries where it is difficult to maintain the immunogen’s cold chain.
Third, Cuban vaccines have proven to be very effective.
“In the clinical studies carried out, an effectiveness of over 90% was demonstrated. However, the most important proof of the effectiveness of our vaccines was the effect obtained in reducing the transmission of the disease in Cuba, starting in October 2021, when the Abdala and Soberana vaccines achieved 60% immunization of the population.
– What effectiveness have Cuban vaccines shown against the Omicron variant?
– Cuban vaccines have been shown to be effective against the Omicron variant, the most infectious of this disease to date.
“The epidemiological evidence shows it. In other words, in Cuba, unlike most countries in the world, the peak of infections with the Omicron variant and its subvariants was lower than the previous ones, including the peak with Delta.
“Without a doubt, the effectiveness of the vaccines developed 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 conducted in Cuba and other countries that the antibodies induced by the Cuban vaccines neutralize the Omicron variant. While some vaccines report up to a 20-fold decrease in the ability to neutralize the Omicron variant of SARS-COV-2, Cuban vaccines only decrease this neutralizing capacity by a factor of two compared to the original.
“This phenomenon that we are observing has its explanation in the type of antigen we use and in the construction of our vaccines.
“The Abdala and Soberana vaccines use the RBD antigen, which is the region of the spike protein (S) that binds to the viral receptor in the cell.
“The RBD antigen was found to induce neutralizing antibodies against a conserved region of the protein among the different variants of the virus, possibly due to the importance of this region for their functionality; therefore mutations in this region of the protein are not selected.
“In immunization with the complete spike (S) protein, however, this conserved region is not immunodominant, which means that antibodies are preferentially induced against other regions of the protein in which there is a high mutation rate, and a process of selection occurs of the variants that escape detection by the neutralizing antibodies.
“Most of the vaccines currently on the market use the spike (S) protein as an antigen, which has produced the phenomenon of consecutive pandemic spikes as a result of the emergence of virus variants that evade the immunity produced by these vaccines.
“We defend the hypothesis that vaccines based on the RBD antigen can provide a universal boost to the rest of the vaccines against COVID-19 by enhancing protective immunity against the different variants of the SARS-COV-2 virus that are or that were in circulation could be generated in the future.
“Recently, several groups of scientists around the world have published articles supporting this hypothesis.”
– How is the international recognition of Cuban vaccines progressing?
– All of these results were published in recognized scientific journals, which means they were appraised by international experts in a so-called peer review process.
“To date, more than 20 scientific articles have been published in influential journals and more reports continue to be produced.
“Cuban vaccines were also evaluated by regulatory bodies from several countries, which eventually granted emergency use authorization.
“Right now, eight countries have granted this approval and others are evaluating it.
«Recently a group of experts and scientists from renowned institutions in the United States, the Caribbean and Africa visited our country and had access to all available information about the results obtained, held meetings with specialists, doctors, scientists and technologists, both in institutions health and biotechnological institutions, recognizing the work done and the quality of Cuban vaccines and issuing a public report.”
– What is the process of evaluating and recognizing Cuban vaccines by the WHO?
–The process of recognition by WHO has started this year, several steps have been taken in accordance with established procedures.
“Information from the Abdala vaccine file has been sent and is being shared with these authorities.
“However, one of the components of the evaluation process is behind schedule.
–The delay stems from the visit by WHO experts to the plants where the vaccines are manufactured.
“We had planned that this visit would take place later this year at the manufacturing facilities of the CIGB-Mariel biotechnology complex, where we are moving the production of the Abdala vaccine.
“Although the production line that will carry out the formulation, filling and packaging operations of this complex is already active and producing, the line that will produce the recombinant products is showing delays in commissioning.
«This delay is due to the inability to make payments to the company responsible for commissioning the equipment and systems of this production line.
“We spent nine months trying to make the payments, which failed due to several banks refusing to make the transfer.
“Despite these difficulties, progress is being made and we hope that the WHO assessment process will be completed in 2023.”