The COVID-19 vaccine at Sinovac Biotech may not provide sufficient antibody responses against a new variant identified in Brazil, a small laboratory study showed.
The emergence of variants of the coronavirus has raised concerns that vaccines and treatments developed based on previous series may not work as strongly.
Plasma samples taken from eight people vaccinated with CoronaVac at Sinovac failed to effectively neutralize the P.1, or 20J / 501Y.V3, line variant, researchers said in a previous paper published Monday ahead of peer review.
“These findings suggest that the P.1 virus may escape from neutralizing antibodies caused by … CoronaVac,” said researchers at the University of São Paulo in Brazil, University School of Medicine Washington in the United States and a few other institutions in the paper.
CoronaVac is used in large vaccine campaigns in countries including China, Brazil, Indonesia and Turkey.
Although the study suggests that relapse may occur in individuals who have received the vaccine, the protection afforded by CoronaVac against severe COVID-19 may reflect other mechanisms in a system Human immunity, in addition to antibodies, may also contribute to the reduction of disease severity, researchers said.
A Sinovac spokesman was not immediately available for comment. Chief executive Yin Weidong said in a program broadcast by state-sponsored broadcaster CGTN on Thursday that the company is “fully capable” of using conventional research and manufacturing capability to develop a new vaccine against changes if that is necessary.
He also said the process would take much less time than it would take to develop CoronaVac.