The Butantan Institute and the government of the state of São Paulo asked Anvisa to authorize the application of the Coronavac vaccine in children from three years of age. 12 millions of doses, which is sufficient for this age group in the state. The decision of the regulatory body in this regard should be made in early January.
The order takes place in the same month that a study on the safety of Coronavac
was published in more than 480 young people over the age of three to 12 years, conducted by Bihua Han, who does medical research at the Center for Disease Control and Prevention in Hebei Province, China, and partners, some affiliated with Sinovac, which makes the vaccine. The researchers observed mild to moderate adverse reactions, with pain at the application site being the most common complaint , and more pronounced in teenagers than in children. Of the few more serious effects observed, none were attributable to the action of the vaccine.
They conclude in the study that this vaccine is safe for the group, observing an immune response to the inoculation in 96% of young people. The result of this Chinese study is corroborated by a smaller study by infectious disease physician Eder Gatti Fernandes, from the São Paulo State Department of Health, and colleagues. The study involved 23 children between seven months and five years old accidentally inoculated with a dose of Coronavac in Brazil. Five of them already had signs of having been infected before with COVID-19, but all, after accidental inoculation, developed a robust immune response. It is important to remember that these small samples do not capture rarer possible adverse effects.
Coronavac is a vaccine based on the old virus inactivated method, as opposed to recombinant virus (AstraZeneca) and fat nanoparticle containing messenger RNA (Pfizer-BioNTech or Comirnaty — trade name of the Pfizer vaccine that came with its approval in the US last September). Therefore, given the method’s familiarity and its effectiveness in immunizing children against other diseases, this Chinese vaccine may offer hope for parents concerned about unknown long-term effects of vaccines based on the newer methods. In addition, the inactivated virus would be the closest to natural immunity, as it presents more targets on the surface of the virus to the immune system. However, as is well known, Coronavac has limited efficacy compared to mRNA vaccines.
Covid-17 is usually a mild disease in children, presenting in many cases, possibly in most of them, in an asymptomatic form.