The director of Instituto Butantan, Dimas Covas, said on Monday(19) that of all the vaccines that are under development and that are being tested against the new coronavirus, the Chinese vaccine, CoronaVac, is the safest. This means that it has not presented serious side effects.
“The Butantan vaccine is the safest in terms of side effects. It is the safest vaccine right now not only in Brazil, but in the world,” said Dimas Covas.
Studies conducted in Brazil with 9,000 health volunteers, aged between 18 and 59 years, have proven the safety results that had already been recorded in phase 1 and 2 tests in China. In Brazil, only 35% of these 9,000 volunteers had mild adverse reactions after the application of the vaccine, such as pain at the application site or headache. There was no record of a serious side effect during testing,
The most common reactions among study participants after the first dose were pain at the site of application (19%) and headache (15%). At the second dose of the vaccine, the most common adverse reactions were pain at the site of application (19%), headache (10%) and fatigue (4%). Low fever was recorded in only 0.1% of participants and there are no reports of severe adverse reaction to the vaccine to date. “Of the other vaccines, none were less than 70%. All but Butantan vaccine had grade 3 side effects, the most important effects when evaluating a vaccine. The Butantan vaccine had no grade 3 side effect,” said Dimas Covas.
Phase 1 and 2 studies done in China with 50,027 Chinese volunteers, among them, employees of Sinovac itself, had already demonstrated that only 5.36% of the vaccinated people had side effects, all without severity: pain at the site of application (if found in 3.08% of volunteers), fatigue (1.53%) and mild fever (0.21%). Slightly more serious effects were observed in 0.03% of volunteers, such as loss of appetite, headache, fatigue and fever.
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