During the CoronaVac Symposium, which will be promoted by Butantan in partnership with Sinovac on days 7,8 and 9/2, researchers from China will present the main results of their studies about the vaccine that will prove its safety and efficacy. The researches points that CoronaVac is safe for children and eldery and that the dose of reinforcement is capable of potentializing the immune response, including against the variants, without provoking adversal reactions.
On the first day of the event, at 8h30, the vice-president of Sinovac, Yaling Hu, responsible by the P&D operations, will speak about the historical creation of CoronaVac, since the cells tests and in animal models, followed by clinical tests of phase 1 and 2 developed in China, until the clinical studies of phase 3 initiated in Brazil on july of the last year. The essays were randomic, double-blinded and controlled by placebo.
Yaling Hu is part of the specialist group of World Health Organization (OMS) and is a senior specialist in vaccine development, leading clinical studies and quality evaluation for the last 10 years, including vaccines against H1N1 and the H5N1, besides CoronaVac.
The clinical phases 1 and 2 in China had 744 health volunteers with age between 18 and 59 years old. The individuals that received both of the doses presented an immune response with seroconversion tax of 90% to neutralizers antibodies. Besides, there were not reported serious adverse effects and the most common reaction was the pain on the local of the vaccine. Afterwards, the results of phase 3, conducted on Butantan with 13 thousands of volunteers, showed an global efficacy of 62,3% if the gap between both doses was of 21 days or more.
Reinforcement dose
On the second day, at 9h20, Xiangixi Wang, main researcher of the Infection and Immunity Lab of the Immunity Institute of Biophysics form the Chinese Science Academy, will present the results “A third dose of inactivated vaccine augments the potency, breadth, and duration of anamnestic responses against SARS-CoV-2” published in preprint platform MedRxiv. The study indicates that, four weeks after the application, the reinforcement of CoronaVac multiplied the levels of neutralizing antibodies against protein S, responsible for the entrance of SARS-CoV-2 on human cells. Besides, the dose elevates the protection against variants, with elevation in 17 times the level of neutralizing antibodies against the delta variant and against the original strain of Wuhan, in 18 times against the alfa variant, in 19 times against the beta and in 14 times against the gama.
Protection of eldery and children
During the last day of the symposium, at 8h30, the researcher Hongjie Yu, professor of the Public Health College from Fudan University, will speak about the immunogenicity of CoronaVac among eldery. A research published in August in the preprints platform MedRxiv followed 303 healthy individuals above the age of 60 to analyze the immunity permanence after the vaccination and the effects of application of a third dose.
The volunteers who received an additional dose of the vaccine eight months after the second dose presented an raising of 7 times on the level of neutralizing antibodies, Besides, the reinforcement dose did not provoke significant adverse reactions. The safety of CoronaVac to eldery patients was shown in another Sinovac study, published in february at the Lancet Infectious Diseases.
The next lecture, at 9h20, the pharmacovigilance manager of Sinovac, Jiayi Wang, will talk about the safety of CoronaVac on children. Clinical studies of phase 1 and 2 of the chinese biopharmaceutical indicates that the vaccine is safe to the population between the age of 3 and 17 and is capable of inducing a high immune response.From 550 of the children and teenagers who took participation in the study, 96% presented antibodies 28 days after the second dose. Preliminary studies of phase 3 reinforce that the immunizing is safe for that public.
China was the first country to approve the use of CoronaVac on individuals above the age of 3 - Today, Chile, Ecuador and Indonesia have already applied the vaccine on children.
Efficiency on people with comorbidities
The safety and immunogenicity of CoronaVac on individuals with chronic diseases and immunosuppressed will be the theme of the lecture at 10h on day 9, which will be conduzed by Zijie Zhang, main researcher of the System Biology Group on the State Lab of Utilization and Conservation of Bio-Resources at the University of Yunnan, on China.
Evidence already proves that the Butantan and Sinovac’s Vaccine is safe for individuals with comorbidities. An article published by Chinese researchers at the SSRN platform, for example, pointed out that CoronaVac protects people with HIV. The study was made with 129 people that live with HIV and 53 negative-HIV individuals, between the ages of 18 and 59. The results indicate that people with HIV can reach a high level of immunity, similar to the one seen on negative-HIV individuals.
Another chinese study recently published at the Cellular & Molecular Immunology magazine, from Nature group, testifies that CoronaVac is able to protect patients with B hepatitis. According to the research, the participants who received the second dose of the immunizing presented a tax of seroconversion of 87,25% for lgG antibodies, and of 74,5% for the neutralizing antibodies.
