Scientists from different countries will attend the CoronaVac Symposium, on the 7th, 8th and 9th of December, to discuss scientific data on the vaccine from Butantan and Sinovac. On the third day, the table on subpopulations and patients with comorbidities will be mediated by researcher Rafael Franco, from the University of Barcelona, who led a study that concludes that inactivated virus vaccines, such as CoronaVac, are more effective in controlling the pandemic by inducing a broader immune response.
The article shows that countries that have adopted inactivated virus immunizers as their main vaccine, such as Chile, Uruguay and China, have had a better performance in reducing the number of Covid-19 cases compared to countries such as the United States, Israel and the United Kingdom, using messenger RNA and adenovirus viral vector vaccines. Despite high vaccination rates, these countries have experienced a considerable increase in cases due to the more transmissible delta variant.
Because it is made with all fragments of the inactivated virus, the most accepted and consolidated strategy in the world, CoronaVac allows our immune system to recognize more virus proteins in addition to the Spike protein – target of other vaccines –, making the immune response more comprehensive. New immunizing technologies provide high protection against the original strain of SARS-CoV-2, but tend to lose effectiveness with the emergence of new variants.
The authors draw attention to the fact that several countries have faced new waves of infection even with a large number of vaccinees. “In Spain, for example, at the end of July 2021 we were on our fifth wave and there is evidence that a sixth wave will come. In nursing homes where all residents were vaccinated (over 90% with messenger RNA vaccines), new cases also emerged. This was not expected at the start of vaccination”, the researchers point out in the article.
The scientists' conclusion is that the administration of CoronaVac and other inactivated virus immunizers would be a more efficient strategy to obtain collective immunity. This technology allows for a diversified production of antibodies, both neutralizing – which help to prevent the infection of cells – and non-neutralizing – important to prevent viral replication, as they help other cells in the immune system to recognize the infection and fight it.
