As the coronavirus continues to spread throughout the world, with Latin America as the epicenter of the pandemic, hundreds of scientific teams are working around the clock to find a vaccine. The partial result: 165 candidates, 6 of whom are already at the most advanced stage and may be available by the end of this year.
Confirmed infections have multiplied by five in the last three months and the global number rises to almost 20 million infections and 715,000 deaths – 30% of them in Latin America – so count on not one, but several vaccines are a priority to control the virus and make a safe return to normalcy.
“The entire sector works tirelessly towards a common goal: to find safe and effective vaccines as quickly as possible”, explains the executive director of the Latin American Federation of the Pharmaceutical Industry (Fifarma), Rafael Andrés Díaz-Granados, who highlights that this “race” against the virus “is” a challenge for humanity “.
165 REGISTERED CANDIDATES
Vaccine trials started with small in vitro or animal safety studies (pre-clinical trials) and, with the results obtained, the phases of clinical trials in humans were allowed to start.
To date, the World Health Organization (WHO) has registered 165 candidates for the vaccine: about 140 are still in the pre-clinical phase, including two from Brazil and one from Argentina, and almost 30 have already been tested on humans.
Of these, six have already entered the final stretch (phase III), in which safety and effectiveness are assessed with tens of thousands of volunteers before regulatory approvals and distribution.
These do not include, however, the one announced by Russia, which is in the last phase of the tests and can be inoculated for a part of its population since October, something about which the WHO has been cautious.
WHAT KINDS OF VACCINES ARE THERE?
Vaccine candidates seek to provide an antigen that itself does not cause disease, but that elicits an immune response and blocks or kills the virus if a person becomes infected.
There are four general platforms working to achieve this: the use of the virus itself, attenuated or inactivated; viral vectors, that is, the use of modified viruses; genetic instructions (DNA or RNA) for the body to replicate a coronavirus protein and generate an immune response directly to the SARS-CoV-2 proteins or protein subunits.
On this basis, virtually all research teams have formed alliances.
An example is the protein vaccine project developed from a flu against the French Sanofi and with the “adjuvant” technology for pandemic use of the British GSK, which can reduce the amount of protein needed per dose and multiply production.
THE MOST ADVANCED
Three of the six most advanced vaccines that may be available this year are developed in China, while the others are from the American pharmaceutical companies Pfizer (which works with German BioNTech) and Moderna and the British AstraZeneca, the latter in collaboration. with the University of Oxford.
The three Chinese are based on the inactivated virus, the two of American origin use RNA techniques and the Astrazeneca’s focuses on a viral vector.
In the case of Pfizer, the “‘messenger RNA’ is used, a copy of the genetic information that the virus has, from which it produces the key (protein) it uses to enter the human cell and cause infection”, Alejandro Cané, chief of North American scientific affairs from the company’s vaccines division, he explains to Efe.
Cané argues that this technology is safer because the entire virus is not manipulated and allows the production of a large amount of vaccine in a shorter period and on a large scale.
The clinical phase was also accompanied by Janssen, from Johnson & Johnson, whose prototype, single dose, uses AdVac technology, with an adenovirus (AD26) as a vector and which was also used successfully in his vaccines against HIV, respiratory syncytial virus and zika.
AN UNPUBLISHED SPEED
The WHO, which declared the pandemic on March 11, predicted it would take at least a year and a half to find a vaccine, but rapid progress has fueled hopes that time will accelerate.
“The usual time to get a vaccine is 10 years. In history, the fastest has ever been licensed is the mumps vaccine, which took about 5 years, but with the coronavirus we are trying to do it between 12 and 18 months” , says doctor Eduardo Ortega-Barria to Efe, vice president and director of Clinical Research for Latin America at GSK.
According to experts, this extraordinary speed has been achieved through strategic alliances between pharmaceuticals, biotechnologies and universities and with an advanced production system, before knowing whether clinical trials will provide the expected results.
“It is a production at risk. They manufacture with their fingers crossed. If the vaccine is not successful, they will see their investment lose. But if it works, they will have a very short time to distribute it,” says the director of the Fifarma.
This is Janssen’s plan, proposed to deliver more than one billion doses over 2021, for which, before the final demonstration of effectiveness and in parallel with the studies, he plans to advance production and evaluate his system. distribution, explains its vice president of Medical Affairs for Latin America, Josué Bacaltchuk.
Experts agree that, given global demand and a population of 7 billion people, it will take a lot of speed and several vaccines, as no manufacturer has the necessary scope of production.
“We must be vigorous: we need several vaccines to meet the WHO objective of initially covering 3% of the population, including health professionals and populations at greatest risk, and then 20% of the adult population. Vulnerable or with comorbidities”, warns Bacaltchuk.
LATIN AMERICAN QUOTES
Brazil remains at the forefront of Latin America by betting on clinical trials from the University of Oxford and the Chinese laboratory Sinovac, both in the third and final clinical phase, and in Pfizer with BioNTech.
Argentina was also chosen by Pfizer and BioNTech as one of the sites for its clinical studies with thousands of volunteers.
In the meantime, Mexico has just announced that it will host phase 3 trials of a French Sanofi-Pasteur vaccine, in which 35,000 volunteers are expected to participate globally.
As for self-research, two Brazilians stand out in the pre-clinical studies listed by WHO, one from the University of São Paulo and the other from the Oswaldo Cruz Foundation, at the Butantan Institute.
The latter seeks to use the influenza virus as a vector for the body to produce antibodies against the new coronavirus.
In the case of Argentina, there are two vaccines under development based on proteins. One, which is explored with adjuvants, is included in the global list of preclinical studies and is developed by scientists at the University of San Martín and the National Council for Scientific and Technical Research.
The other, promoted by experts from the University of the Coast, proposes “to develop a vaccine candidate based on virus-like particles (virus-like particles)”, although it is not on the WHO list.
The same applies to a study by the National Autonomous University of Mexico (UNAM), in which they identified regions of the virus that may have a great capacity to induce an immune response.
“We already have very promising results. We have identified a peptide capable of effectively inducing antibodies,” said researcher Edda Sciutto to Efe, adding that his idea is to design a vaccine that can be applied by injection or intranasally.
Diana Marcela Tinjacá