The first cases of Covid-19 were identified in December 2019, and the SARS-CoV-2 virus was described in May 2020. During this period, Sinovac, Butantan's partner in the development of the CoronaVac vaccine, was already running to work in the production of vaccines to protect the population focusing on four aspects: safety, quality, ability to maintain the supply chain and production efficiency.
During the CoronaVac Symposium, the Vice President of Sinovac, Yaling Hu, explained about the development process of the immunizer, which is manufactured with the inactivation of SARS-CoV-2. Several points were considered, such as the clear identification of the origin of the strains, confirmation of the absence of microorganisms or exogenous contaminating agents, stable growth characteristics of the strains, satisfactory immunogenicity and a robust antiserum reactivity towards the prevalent strains.
"We've had rapid results thanks to the accumulation of experience in the development of inactivated vaccines over the last 20 years," said Yaling Hu, who is responsible for the research and development operations of the Chinese pharmaceutical company.
The manufacturing process includes technology platforms, which leverage breakthroughs, efficient and fast processes for adopted production strategies and the ability to maximize and adapt processes for large-scale production – such as substitution and addition of raw materials. For virus cultivation, three bioreactors were used to collect six million doses in a single batch.
“We tried to do as much as possible to shorten the process and improve processing capacity, ensuring that commercial production capacity was reached. All steps can be guaranteed within 24 hours, with virus purity over 99%,” said Yaling Hu. With the inactivated virus vaccine technology, the production capacity has been increased by 100 times compared to other conventional vaccines.
Now, the Butantan partner is working on adapting CoronaVac to combat the new omicron variant. According to the vice president of Sinovac, the first step is to isolate the new strain of virus and carry out a neutral antibody test. Afterwards, evaluations and clinical studies will be carried out in different age groups. The forecast is that the survey will be completed in three months.
At the end of his speech, Yaling Hu thanked Sinovac's partners in developing the vaccine, which, in addition to Butantan, includes 25 Chinese and foreign laboratories and research institutes, five hospitals and the China Center for Disease Control and Prevention.