The largest global study ever conducted on the effectiveness of the Pfizer/BioNTech vaccine in people aged 12 to 17 indicated that it could protect up to 93 percent of this public against the development of symptomatic forms of Covid-19. The results were published on Wednesday (20) in the scientific journal The New England Journal of Medicine.
Researchers from Clalit Research Institute in Israel and Harvard University in the USA analyzed the data of 94,354 vaccinated Israeli adolescents and an equal number of unvaccinated ones.
The study was conducted between June 8 and September 14 this year, when the country was facing a spike in infections caused by the delta type of coronavirus. With this, it was also possible to analyze the effect of the vaccine in relation to this strain.
A 93% protection rate against cases of Covid-19 symptoms was observed between one and three weeks after the second dose was applied. For cases where infection was confirmed, the efficacy was 90%.
The group also analyzed the rate of protection for those who only took one dose. In this case, the rate was 57%, a result considered “substantial”.
“There was insufficient data to provide an estimate of the decrease in the incidence of severe disease, hospitalization and mortality because such outcomes are rare among adolescents,” the study authors said in a statement.
Israel was the first country to begin vaccinating adolescents. Even in January, children aged 16 to 17 were already able to receive the vaccine. The immunization was extended in June to the public over the age of 12.
Until then, the scientific data available was from a study sponsored by Pfizer itself, with 1,983 teens, which worked to obtain authorization for use from regulatory agencies, including Anvisa (the national health watchdog agency).
Here is a vaccine Pfizer is licensed for use by persons between the ages of 12 and 17 as of June 11. However, the request was initiated by a decision of the states themselves.
Only on September 22 Ministry of Health decided that adolescents without comorbidities could be vaccinated.
The ministry even issued a guide invalidating the immunization of this category, but it retracted.
According to data from the Ministry of Health, 10 million adolescents have already received the first dose of the Pfizer vaccine, while 271 thousand have completed the vaccination schedule.
