Since the pandemic broke out, dozens of research groups in different countries seek to create vaccines against covid – 19.
Some of them are in Latin America, such as Cuba, which began this month the last phase of the trials of two of the five candidates he is developing.
In Mexico, the Secretary of Health, Jorge Alcocer Varela, recently said that before the end of this year his country could have “a vaccine developed by Mexican scientists “.
And the thing is that behind this objective there are several projects in that nation.
One of them It is the one led by the biochemist and immunologist Edda Sciutto, at the Biomedical Research Institute of the National Autonomous University of Mexico (UNAM).
Preclinical phase
According to the researcher, who has 30 years of experience in vaccine development, the candidate they have created is a molecule, a part small spike protein, which is what the virus uses to penetrate human cells and infect them.
Together with Alpharma Laboratories, they have advanced in the preclinical phases, with “very promising” results .
“The vaccine candidate formulated for human use was tested in mice, in which it induced a potent high-level response of neutralizing antibodies; that is, they are capable of inhibiting the entry of the virus into the cell “, the expert tells BBC Mundo.
” In the case of pigs, we tested different doses to be able to get closer to the which is suitable for humans, and the three doses evaluated elicited high levels of neutralizing antibodies , similar to those of convalescents. ”
Rate the Potential “very safe” vaccine, since it follows “all requested international guidelines.”
It has been designed to inject two doses, at different times, intramuscularly.
“The The advantage of being a very simple (manufacturing) platform is that we can quickly modify the composition of the vaccine, reformulating it with the sequences of the viral strains that prevail “.
All efforts, indicates Sciutto, are focused on completing the preclinical studies and starting phases 1 and 2, which are the stages in which the biological compound is tested in people.
“The design of the phase 3, but surely there will be tens of thousands of people , as it has to be. ”
This project has the collaboration of several organs and health institutes of Mexico.
“We hope that in May the trials in people can begin and that in the course of this year we will be able to have a Mexican version of the vaccine, if the results that we hope. ”
“ This pandemic is enlightening us about the importance of having national vaccines and not depend as currently happens on the arrival of vaccines (from abroad) to be able to vaccinate in Mexico. ”
In the south
The World Health Organization offers a list of vaccine projects against covid – 19 that are in preclinical development (184) or clinical (83) in different parts of the world.
Clarifies that the inclusion in that list does not constitute and should not be construed as an endorsement or endorsement by WHO of such product or entity.
Among the candidates for vaccines in the preclinical phase can be found a project from the University of Sao Paulo and another from the Butantan Institute, which, on Friday, reported that it requested authorization from Brazilian regulatory entities to start clinical trials in humans.
“It is a historical announcement for the world. The vaccine 100% national , with promising evidence and the result of the work of an institution of 120 years of existence, which is the largest producer of vaccines in the Southern Hemisphere ”, declared Joao Doria, governor of São Paulo, at a press conference at the state laboratory headquarters.
The technology behind that Brazilian candidate, which they have named Butanvac, is similar to the one used for the flu vaccine.
Another initiative is taking place at the Institute of Biotechnological Research at the National University of San Martín, in Argentina, and it is in the preclinical phase.
Juliana Cassataro, researcher at that study house and at the National Council for Scientific and Technical Research (Conicet ) leads the group that “has identified two candidate vaccine formulas ,” he told BBC Mundo.
According to the expert, the formulas evaluated in animals “induce virus neutralizing antibodies and T response”.
The possibility of a mucosal vaccine
Also in Argentina , Another project is headed by researchers from the National University of La Plata and Conicet Guillermo Docena and Omar Azzaroni.
It is based on the use of fragments of protein S (located in the coat of SARS-Cov-2, the virus that causes covid – 19)) and seeks to “encapsulate those fractions of the protein in nanoparticles and inoculate them to generate the necessary antibodies that allow blocking the entry of the virus, and provoke the memory response that guarantees protective immunity over time “, reported the Conicet.
” In principle, the idea is to use this method for the development of a systemic vaccine, which could be applied, for example, intramuscularly, as is the case with those obtained for covid – 19 “, said Dozen.
To which he added:” But we also evaluate the possibility of doing it in a mucosal vaccine; that is, it is applied to the mucosa, either intranasally or orally “.
Once the team finds “the experimental conditions to induce the best immune response” and can characterize those antibodies, they will go on to study in animals.
“We hope to conclude these stages during the course of 2021, to then evaluate the possibility and conditions of going to clinical phases “, indicated the researcher.
From birth
A project that is in the stage of preclinical studies is in Chile.
Alexis Kalergis, director of the Mi Institute lenio of Immunology and professor and researcher at the Pontificia Universidad Católica de Chile, explains to BBC Mundo that for a vaccine to be successful it must confer specific immunity, because it is more efficient and durable.
“However, one of our vaccine prototypes is based on a formulation that, by itself, is capable of inducing trained immunity against SARS-CoV-2 “, he points out.
And he adds: it is” a characteristic that has been published by our scientific group, and that we have used in other formulations against other pathogens, such as respiratory syncytial virus or metapneumovirus. ”
But this type of immunity is a p nonspecific and short-term process.
“Therefore, virus components must be included in vaccine formulations to induce specific immune responses, which is what we are doing.”
The biochemist and his team are designing the candidate so that it can be used from birth.
“One of our prototypes has the attribute of safety and immunogenicity in the child population “, it indicates.
” It is based on a type of formulation that has been used previously in newborns, adults and older adults. This quality of our formulation distinguishes it from all others that are under development. ”
Although it recognizes that the creation of a vaccine is a process that can be long and whose deadlines are difficult to predict, is optimistic.
“We believe that we will continue to advance permanently and effectively, we hope to be able to conclude the preclinical stage this year and from next year to achieve what is necessary to start the first clinical studies.”
Genetic platform
In Ecuador, the Escuela Superior Politécnica del Litoral (ESPOL) announced on March 1 that it had developed a vaccine prototype and planning to begin collaborative preclinical testing in the coming months with the National Institute for Public Health Research (INSPI) and the University of the Armed Forces (ESPE).
According to a statement from ESPOL, the team, led by the head of the Laboratory for Biomedical Research of the School of Life Sciences, Washington Cárdenas, analyzed the genetic sequence of the virus and asked (abroad) to synthesize a fragment of it, for which he created a genetic platform.
After cloning the viral fragment, “it was introduced into cell culture to produce the encoded protein.”
And, for preclinical tests, the protein is being purified, that is, it is being isolated.
The objective is to optimize its production process because it is “a necessary input to be injected” in the tests that are They will do with rodents.
A vector
The WHO list of candidates for pre-clinical vaccines also includes the work of Farvet, a veterinary pharmacological company from Peru, which claims to have developed drops to be administered into the nostrils in two doses.
That proposal “uses as vector the Newscastle virus , which causes Newcastle disease in birds and has not been reported to be pathogenic in humans ”, Zimic Mirko, a consultant scientist for the project led by the microbiologist and director of Farvet, Manolo Fernández.
Mirko, who is also a professor and head of the Bioinformatics and Molecular Biology Unit at the Universidad Peruana Cayetano Heredia, explains that a vector is like a kind of Trojan horse that carries the SARS-Cov-2 antigen on its surface and shows it to the immune system.
“All the preclinical studies of safety, immunogenicity, tolerance, toxicity, stability and, in the end, , the evaluation of the efficacy of the vaccine in animals was carried out in a challenge study (with the virus) and the results have been very favorable ”, he pointed out.
After having tested the substance in mice, rats and hamters, clinical trials with humans are lacking.
Each of the three phases of these studies requires that strict ethical requirements and prototypes are met They must be produced following the conditions of Good Manufacturing Practices (GMP).
“We are knocking on the doors of several laboratories in the world, which have GMP certification, that can support us to produce the doses of at least a limited number to do the tests of phase 1 and 2 “.
The expert assures that they have received the advice of the International Vaccine Institute (IVI).
” The most important challenge is to demonstrate that it is safe for humans to use a vaccine like this intranasally and, for that, you need to do the respective clinical trials and have all the permits (from the Peruvian regulatory authorities) . We are aiming for that ”.
This project has been marked by controversy, after Fernández reported that both he and his family and members of his team had tested a prototype.
He later denied that that had happened and said that his statements had been a mistake.
“We have never been vaccinated, we cannot get vaccinated because a permit from an Ethics Committee is required,” he told the Peruvian newspaper Trade.
Evaluation
Before a vaccine candidate is used, it must have the authorization of the regulatory body of the country where it is wanted use.
This will make sure that in each phase all the safety requirements are met for the volunteers who participate and, once all the human trials have been completed, will analyze if it is effective and safe for the population.
Countries can request an evaluation from WHO or the Rotary Fund of the Pan American Health Organization (PAHO), which is “a solidarity cooperation mechanism through which vaccines, syringes and related supplies are purchased on behalf of the participating member states”.
Jarbas Barbosa, deputy director of PAHO, highlighted, in a recent press conference, the importance of having projects for the development and manufacture of covid vaccines – 19 in Latin America and the Caribbean.
The more producers there are in the world, the better, as long as all safety requirements are met.
“The Revolving Fund can only purchase a vaccine that has been previously qualified (by WHO) or that has been included in the WHO list for emergency use,” he indicated.
The sources consulted by BBC Mundo coincide in stating how important the scientific collaboration that has been given has been to stop the covid pandemic – 11 and, although the vaccines that are being used in many countries were developed in record time, historically creating a safe and effective vaccine takes several years.
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