The world is vaccinating against the coronavirus and it is expected that as a certain level of immunization approaches, victory against the pandemic will be a reality. Meanwhile, we continue to discover things about a vaccine obtained in record time.
As the BBC reports in a report , the main objective of the vaccine, to make the symptoms of Covid-19 mild, is being fulfilled. In addition, as observed in places like Israel, the place with the highest vaccination rate, the transmission of the virus is being reduced. But there are other benefits.
In April of last year, the WHO defined the requirements that vaccines should have: a minimum effectiveness rate of 50% against the infection itself, against symptomatic disease or against severe forms of the disease.
The second requirement
The pharmaceutical companies focused on the second requirement: effectiveness against symptomatic disease, with the aim of accelerating the process of creating the vaccine to combat the pandemic.
Thus, the various pharmaceutical companies did the same: Phase 3 clinical trials were designed to establish how much vaccine candidates protect against symptomatic Covid-19.
“We must understand that the vaccine is not like a medicine with which we treat a person. The vaccine is something that protects the community. It cannot be analyzed from an individual point of view, but from how an entire population is protected ” epidemiologist Denise Garrett, vice president of the Sabin Institute, told the BBC.
“The vaccine is something that protects the community. It cannot be analyzed from an individual point of view, but rather from how an entire population is protected”
To demonstrate its safety, each vaccine undergoes several steps: “It all starts with experiments in animal cell cultures, where we see if the molecules have the potential to function in humans, ” Dr. Jorge Kalil, professor of clinical immunology, told the BBC. from the Faculty of Medicine of the University of São Paulo.
If the results are positive, “we start with a limited number of volunteers in phase one and, as knowledge progresses, we evolve to tens of thousands of participants in phase three, ” says Kalil.
“In addition to knowing that CoronaVac had a 50% overall efficacy rate against symptomatic disease, the research showed 78% protection against mild symptoms that also required medical assistance. This was an observed secondary outcome,” exemplifies the Dr. Kalil.
“Vaccines can have an impact on viral transmission, and the more people are protected, the more difficult it will be for the virus to find someone vulnerable.”
These kinds of secondary benefits are well seen in Israel, the country with the most vaccinations. ” It has become a perfect case study, since it is using the same vaccine in the entire population and applying the doses at a very rapid rate,” Natalia Pasternak, president of the Questão de Ciencia Institute in Brazil, tells the BBC.
Data from Israel reveal that the vaccine has already caused a dramatic drop in cases, a reduction in hospitalizations and a decrease in deaths from Covid-19.
“The latest analyzes reveal that unvaccinated individuals are 44 times more at risk of developing a symptomatic infection and 28 times more likely to die from the disease,” revealed the Israeli health authorities.
“This means that vaccines can have an impact on viral transmission , and the more people that are protected, the more difficult it is for the virus to find someone vulnerable,” says Denise Garrett.
A new difficulty has arisen in the battle against the coronavirus: the variants. ” They are worrisome . The vaccines that we have at the moment account for the types of coronavirus that have been described so far. Therefore, we cannot allow margin and time for other versions to appear and escape the solution we have,” Pasternak says.