By Liz Conde Sánchez on December 18, 2022
photo: Leandro Pérez
More than a year after the start of the massive anti-COVID-19 vaccination campaign in our country, Cuban vaccines continue to demonstrate their safety, effectiveness, and capacity to control the pandemic, even when confronting the new, highly contagious variants that have appeared in the world.
Irrefutable evidence of this is, in the first place, the sustained control of this illness on the Island of Cuba, and, in addition, the growing international recognition that the Cuban vaccines have obtained independent of the progress of the WHO (World Health Organization) recognition process.
In an interview, Dr. Eduardo Martinez Diaz, President of the BioCubaFarma enterprise group, directed his remarks to the characteristics that distinguish the Cuban vaccines, to the evidence that shows their effectiveness, to the international recognition that they have achieved, as well as to the WHO evaluation process.
“What characteristics distinguish the Cuban Anti-COVID-19 vaccines?”
“The Cuban Anti-COVID-19 vaccines have several characteristics that distinguish them from others that have been developed. First, they have been shown to be very safe. After tens of millions of doses given, in Cuba and other countries, it has been observed that adverse events are mild and occur at low frequency, including in the pediatric population from ages 2 to 18 years, which is unique in the world up until now. These are not chance results; the nature of the technological platforms utilized and the design of the vaccines warrant them.
In the second place, these vaccines are very temperature-stable. In contrast with others that require special conditions for storage at freezing temperatures, our vaccines can be stored between 2 and 8 degrees Celsius. In addition, they have demonstrated the capacity to 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 difficulties exist in maintaining a cold-chain for immunologic agents (vaccines.)
In the third place, the Cuban vaccines have demonstrated that they are very effective. Clinical studies that have been carried out, they show efficacy greater than 90% but the most important evidence of the effectiveness of our vaccines is the impact that they have had in decreasing disease transmission in Cuba, beginning in October 2021, when we achieved vaccination of 60% of the population, using the vaccines Abdala and Soberana.”
“What level of effectiveness have the Cuban vaccines shown against the Omicron variant?”
“The Cuban vaccines have shown themselves to be effective against the Omicron variant, the most infectious variant of the disease known up to now. Immunological evidence shows this. In other words, in Cuba, in contrast to the majority of countries in the world, the peak levels of infection with the Omicron variant and sub-variants have been lower than earlier peaks, including those with Delta variant.
Undoubtedly, the efficacy of the vaccines created by our scientists against these new strains of SARS-COV-2 and the strategy of vaccination has a great deal to do with this disease behavior here in Cuba. We have found, in laboratory studies conducted in Cuba and in other countries, that the antibodies induced by Cuban vaccines neutralize the Omicron variant. While some other vaccines report a decrease of up to 20 -fold in the capacity to neutralize the SARS-COV-2 Omicron variant, compared to the original strain, the Cuban vaccines show a decrease of only 2-fold in neutralization capacity.
This observed phenomenon is explained by the nature of the antigen that we use, and by the design itself of our vaccines. Abdala and Soberana vaccines use the RBD antigen, which is to say, the region of the Spike protein (S) which links to the receptor of the virus in the cell. It has been found that the RBD antigen induces neutralizing antibodies against a region of this protein which remains unchanged among the different variants of the virus, possibly due to the importance of the said region in the functionality of the virus; because of this, mutations in the zone that codes for this protein are selected against. However, when one immunizes with the complete Spike protein, this preserved region is not immuno-dominant; in other words, antibodies are preferentially induced against other zones of the protein, in which high rates of mutation exist, so that there is a process of selection for the variants that escape the recognition of the neutralizing antibodies.
The majority of the vaccines currently on the market utilize the Spike protein as the antigen, and this has generated the phenomenon of successive pandemic spikes as a result of the appearance of virus variants that escape the immunity induced by these vaccines. We maintain the hypothesis that vaccines based on the RBD antigen can constitute a universal booster for the rest of the vaccines against COVID-19, amplifying the protective immunity against different variants of the SARS-COV-2 virus that are now circulating or that may arise in the future. Recently several groups of scientists in the world have published articles that support this hypothesis.”
What is the progress of international recognition of the Cuban vaccines?
“All these results have been published in well-recognized scientific journals; that is, they have been evaluated by international experts in a process of peer-review, as it is termed.
To date, more than 20 scientific articles have been published in high-impact publications, and more reports are in progress. The Cuban vaccines also have been evaluated by the regulatory authorities in a number of countries, with the final result being to grant Emergency Use Authorization. At this time, eight countries have given this authorization and others are doing their evaluations.
Recently, a group of experts and scientists from prestigious institutions of the United States, the Caribbean, and Africa visited our country and had access to all the available information about the results we have obtained. They met with specialists, physicians, scientists and technologists, both in healthcare facilities and in biotechnological facilities, recognizing the work achieved and the quality of the Cuban vaccines, and issuing a public report.”
“What is the progress of the process of evaluation and approval of Cuban vaccines by the World Health Organization (WHO)?”
“The WHO recognition process began this year and several steps have been taken according to established procedures. Information and documentation of the Abdala vaccine has been sent and exchanged with these authorities. Nevertheless, one of the components of the evaluation process has been delayed. The delay has involved the visit of the experts to the plants where the vaccines are made. We had planned that this visit would take place at the end of this year, in the production facilities of the Biotechnological Complex CIGB-Mariel, where we are transferring the production of the Abdala vaccine.
Although the production lines, in which the formulation, filling and packaging at this facility are carried out, are active and functioning, the line in those areas that manufacture recombinant products has experienced delays in being put into action. This delay has occurred because it has not been possible to make the payments to the enterprise in charge of implementing and starting up the equipment and the systems of this line of production. We have been trying to make these payments for nine months, and they haven’t materialized because a number of banks refuse to engage in the operation of the transfer of funds.
Despite these difficulties, we are moving forward and we hope that in 2023 the WHO evaluation process will be completed.”
Source: Granma, translation Resumen Latinoamericano – US