Before the approval of a safe and effective vaccine against COVID-19, it is necessary to complete the three stages of testing and research with the immunizer. In search of solutions against the new coronavirus (SARS-CoV-2), the National Health Surveillance Agency (Anvisa) has already authorized four clinical studies, with humans, in Brazil. In total, more than 34 thousand Brazilians participate in the tests for potential vaccines.
Among the tests for a vaccine against COVID-19, in progress in the country, are:
- Coronavac: the immunizer of the pharmaceutical company Sinovac in partnership with the Butantan Institute, with 13 thousand participants;
- The formula developed by the University of Oxford and the pharmaceutical company Astrazeneca, with 10,000 volunteers;
- Johnson & Johnson’s pharmaceutical candidate, Janssen, with 9,800 Brazilians;
- The formula of Pfizer with the biotechnology company BioNTech, which adds two thousand volunteers.
All national research initiatives for a vaccine against COVID-19 add up to 34.8 thousand Brazilians, spread over ten states. Among them are: São Paulo; Rio de Janeiro; Rio Grande do Sul; Large northern river; Minas Gerais; Paraná; Federal District; Mato Grosso; Mato Grosso do Sul; and Santa Catarina.
Check the complete situation, below, in the last survey made by Anvisa:
How does COVID-19 vaccine testing work?
The last and third step before approval, phase 3 is done in large-scale tests, with thousands of individuals and from different populations, for a more definitive assessment of the effectiveness and safety of a vaccine against COVID-19. It is in this stage that are the four immunizers tested in Brazil, for example.
However, not all 34,800 Brazilians received potential vaccines against COVID-19. This is because, regardless of what research it is, the volunteers are divided into two groups, where one will receive the vaccine and the other, a placebo (substance without connection to COVID-19), in the so-called randomized study. Thus, the researchers evaluate which of the two groups gets sicker – working with the hypothesis that the vaccinated volunteers will be less sick.
Now, you are probably wondering why so many tests with potential vaccines against COVID-19 are taking place in Brazil. According to the CEO of Chinese pharmaceutical company Sinovac, Yin Weidong, it is because of the severity with which the country was hit by COVID-19, since there are already more than 4.7 million cases. In this scenario, it is possible to assess, more quickly, the protective capacity provided by the immunizer.
In Brazil, the approval of clinical studies depends on four main aspects, according to Anvisa. They are: formula safety data; design of the proposed study; production and quality control data; and good clinical practice. From the presentation and evaluation of this information, it is possible to start human trials of a new drug, as is the case with the potential vaccine against COVID-19.
“The safety data must have already been generated in previous studies, to guarantee the safety of the respective vaccine, and are checked by the team responsible for the analyzes. The study design assesses the scientific robustness (number of volunteers and age group to be studied, statistical approach, parameters that guarantee efficacy and safety results, among others) “, explains the agency about the information necessary for the release of a study.
Once approved, Anvisa continues to monitor the research. It is through this monitoring, for example, that the agency can interrupt a study in cases of serious adverse events – as was the temporary break, of less than a week, with the immunizer produced by the University of Oxford.
“It is worth mentioning that, when the clinical development of a vaccine is entirely conducted abroad [como a vacina russa, por exemplo], there is no obligation to agree [aprovação] prior, by Anvisa, to clinical studies. However, registration remains necessary “, explains the agency. In other words, immunizers and details about them always need to pass the approval of the regulatory agency.
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