Studies show CoronaVac efficient against three coronavirus variants
CoronaVac, the vaccine developed by Butantan Institute and Chinese pharmaceutical company Sinovac, being applied in Brazil, is efficient against the three variants of the coronavirus circulating in the country: the British B.1.1.7, the South African B.1.351, and Brazil’s B.1.1.28, of which are derived variants P.1, from Manaus state, and P.2, from Rio de Janeiro. The information was announced Wednesday (Mar. 10) by Butantan Director Dimas Covas.
Still in their preliminary stage, these studies, conducted by Butantan in partnership with the University of São Paulo (USP), included samples from 25 participants vaccinated in stage 3, carried out by Butantan in Brazil with 9 thousand volunteers, in which the safety and efficiency of the vaccine are gauged. The full study includes a higher number of samples, which are already being analyzed.
“We must ascertain whether the vaccines produce antibodies against these variants. And that’s what we did. We already knew the antibodies produced by the Butantan’s vaccine was efficient against the British and South African variants. And now a study carried out in association with USP shows that the inoculation is also efficient against variants P.1 and P.2. Therefore, we’re looking at a vaccine that’s effective in protecting against the variants circulating right now,” Covas stated.
Inactivated virus
The vaccines made with the inactivated virus, like the one produced by Butantan Institute, have all the parts of the virus, the biological research center reports. This may generate a more comprehensive immune response compared to what happens to other vaccines using only a part of the spike—the protein used by coronavirus to infect cells.
Another property of Butantan’s inactivated vaccine is the fact that it includes a complete spike protein. The vaccines with smaller fragments of this protein may display lower chances of efficiency against the new variants.
The tests run by Butantan use the serum from vaccinated people, which is collected through a blood test. The samples are placed in a cell culture and subsequently infected with the variants. The neutralization consists in pinpointing whether the antibodies generated as a result of the vaccine will neutralize the virus in the culture.
Variants
“Variants are new forms of the same virus. Some variants have extremely alarming characteristics,” the director of Butantan Institute pointed out.
Roughly speaking, three variants of the novel coronavirus are currently circulating in Brazil: the British B.1.1.7, the South African B.1.351, and Brazilian B.1.1.28. Brazil’s variant gave rise to P.1 (from Manaus), considered the most aggressive, and P.2 (from Rio de Janeiro). Studies have shown that the variants may be more transmissible and even more severe.
“The UK variant has transmissibility among people increased from 30 to 50 percent, and the severity of cases went beyond 30 percent. There is also the South African variants, which exhibits an increase in infected people’s viral load and transmission, in addition to resisting the neutralization of antibodies produced by some of the vaccines and even by natural infection,” Dimas Covas went on to say.
Predominant among Brazilian variants is P.2, which came into existence late last year and shows a similar mutation to that of South Africa. “However, the most is important one is Manaus’s P.1, which concentrates mutations observed in the variants of both UK and South Africa. Therefore, it is a variant that’s concerning and partly explains the seriousness of the present moment of the pandemic,” he warned.
