Author: Yaditza del Sol González | internet@granma.cu
Author: Gladys Leidys Ramos López | internet@granma.cu
Author: Maby Martínez Rodríguez | internet@granma.cu
Author: Yudaimi Castro Morales | internet@granma.cu
April 29, 2021 01:04:21
What does a vaccine do? What does it protect us from? Is it possible for a vaccinated person to be PCR positive? With these questions that, according to Vicente Vérez Bencomo, general director of the Finlay Vaccine Institute (IFV), are the cause of many doubts in the population, he began his intervention this Wednesday in the Roundtable program, an issue in which he was updated on the results of the clinical trials of the vaccine candidates and their productive escalation.
"The answer to all these questions - explained Vérez Bencomo - is perhaps." Because we have to understand that there are at least five things that can occur during COVID-19 infection, he said during his presentation, which he dedicated to the prominent researcher Gustavo Sierra, author of the VA-Mengoc-BC vaccine, who died the day before , because of COVID-19.
The first thing that can happen, he continued, is to contaminate us with the virus, mainly through airways. If the virus manages to overcome our defenses, it attacks us, and by then we would be talking about the disease. In both cases, whether we are asymptomatic infected or develop the disease, we can transmit it, he said.
"Once sick, people can evolve to what is called the need for intensive care, and they can die."
Each of those five stages, he noted, is related to the levels of immunity a person has. "Although the numbers are not exact, it has been shown that the levels of immunity that humans need to prevent death from this disease are relatively low."
Now, the levels that are needed so that a person does not transition from moderate disease to intensive care are higher, and to avoid getting sick are even higher, compared to the previous phases; the same for not transmitting and, so on, he detailed.
Explaining what happens with a three-dose vaccination, the IFV Director General said that, with just one dose, there are people who already reach a level of immunity that protects them from becoming infected; however, other people do not. With a second dose, there will be many more that reach that level of immunity; and with a third, it is reinforced. By this we are saying that it is possible that the vaccine protects against infection, but not to the same extent that it will protect against disease.
Referring to the vaccination scheme of two doses of Soberana 02 and one dose of Soberana plus, the also doctor of Sciences stressed that this combination has yielded very good results, especially in phase IIA.
«This combination culminated a phase I of clinical trials with very good results, with a percentage of people with very high virus neutralizing antibodies, which allowed us to go to phase II, which was divided into two parts: a phase IIA and a IIB ».
He spoke of a phase IIA, with one hundred subjects, open and without placebo, which concluded with very good results and confirmed that two doses of Soberana 02 and one of Soberana Plus was the best formula for the Soberana 02 vaccine candidate.
He explained that phase IIB was held at two sites in Havana, and is nearing completion. «We are in the evaluation of the last serums. This included 810 people, with a relatively small placebo group, which allowed us to have a statistically valid result when comparing the immune response.
Vérez Bencomo highlighted that, currently, a phase II trial with Soberana plus is being carried out in 450 convalescents from COVID-19, and it is planned to carry out, in the month of June, a large vaccination campaign with this group, which, statistically, is not so big, if we compare it with the rest of the population.
"We are awaiting authorization from the Center for State Control of Medicines, Equipment and Medical Devices (Cecmed) to initiate a phase I / II clinical trial in the pediatric population." Initially, it will start with the age range of 12 to 18 years, and then, under 12, he said.
This trial, he specified, will take place around the Juan Manuel Márquez hospital, and part of the comparisons will be based on whether Soberana 02 plus Soberana plus is applied, or three doses of Soberana 01.
He pointed out that phase II of Soberana 01 is under design, which will take place in the province of Cienfuegos, and "we do not expect to take too long to present the file for authorization by Cecmed."
OTHER RELEVANT ISSUES ABOUT CUBAN VACCINES
Regarding the differences between Cuban vaccine candidates and those developed in other countries, Dr. Vérez Bencomo said that ours are based on known platforms and, therefore, there is experience and results in this regard, which is not the case with the new formulas that they are being used in other injectables, as there has not been enough time for observation.
In terms of advances, he acknowledged, these developments are important, but it must be borne in mind that the knowledge of genetics is about 68 years old, so the use of viral RNA in a vaccine raises questions and concerns in experts .
In contrast, he argued, Cuba opted for more conventional technologies with greater testing, where the risks are lower. Specifically, about Soberana 02, he reviewed what constitutes a conjugate vaccine.
These vaccines have very important properties. First, he mentioned, they have the ability to generate an immune response in infants; they also have the capacity to generate immunological memory, induce maturation of the response. They also generate a response in the mucosa, which has the ability to eliminate the carrier state of bacterial pneumonia, for example.
In the case of a virus, he compared, the interaction with the mucosa is different; but the fact that conjugate vaccines achieve an immune response in this area is a decisive discovery.
Therefore, he added, at the base of Soberana 02 is the conjugation of the virus antigen with tetanus toxoid, which has a very solid scientific basis, and whose reviews with the scientific community are progressing very well.
Referring to the IFV vaccine production process, Vérez Bencomo pointed out that the Molecular Immunology Center produces the rbd antigen of the virus, and the ifv plants are in charge of the tetanus toxoid and the chemical process of conjugation, the scaling of which is sufficient , but work is being done to increase it, if necessary. Meanwhile, in the National Center for Biopreparations (BioCen) the active ingredient is formulated, filled and transformed into bulbs.
In fact, Dr. Gabriel González García, BioCen's director of production, argued that the task of this institution in the development of the Sovereign series vaccine is to guarantee production on an industrial scale, in an environment of compliance with good practices. There the formulation, aseptic filling, optical inspection and packaging are done.
Regarding the productive capacity, he highlighted that in the parenteral plant 2 there is a formulation capacity of 200 liters per day, and a filling capacity of 120,000 bulbs per day, while in the parenteral plant 3 there is a formulation capacity 300 liters per day and a filling capacity of 120,000 bulbs per day.
He explained that there is a revision and packaging plant, where they have the three known optical inspection methods: manual, semi-automatic and automatic. In the case of the automatic method, there are two inspectors that can inspect more than 20,000 bulbs per hour.
ABDALA'S PRODUCTIVE OUTPUT TAKES PLACE IN AICA LABORATORIES
The general director of the Aica Laboratories, Antonio Vallín García, said that the productive scaling that takes place in the industry is a huge challenge, especially for this institution.
According to statistics, aica is a 100% state-owned company, with five manufacturing facilities, which has 190 products that are taxed on the basic table of medicines, which means almost 55% of the basic table that is manufactured in the country.
Each year, aica manufactures, on average, between 120 and 140 million sterile doses, which is increasing with the incorporation of serum and blood products, products of which are also produced millions.
According to the manager, one of the biggest challenges for aica has been to assume the productive exit of the vaccine candidate Abdala, for which they had the support of BioCen, CIGB, CIGB Mariel, and practically all the institutions of the BioCubaFarma business group .
Vallín García added that aica was released, last year, working with the Nasalferón, since they started with the CIGB, then they went through Abdala, once BioCubaFarma gave them the challenge of manufacturing it, and today they work, again with BioCen, in the manufacture of conveyors for PCR samples.
Regarding the production capacity of aica, the manager assured that it is very high. Only in the entity there are ten million vials that in the year are one hundred million doses. The same happens with other production units of the company, where it can also be manufactured on a large scale.
It must be said that these capacities have been generated over more than 20 years of permanent state investment in these standards. Aica's capabilities allow for virtually 280,000 to 300,000 doses of vaccines to be manufactured every day, he noted.
