Sinovac booster effective for Sinovac primary recipients

by TMR / pic by TMR FILE

PRELIMINARY results from an ongoing study have shown that Sinovac vaccine booster can activate cellular immunity against Omicron variant, in subjects who previously received two doses of the vaccine as primary series.

The study is being carried out by the Pontifical Catholic University of Chile (UC) and led by Professor Dr Alexis M Kalergis, director of Immunology and Immunotherapy Millennium Institute.

Its objective is to evaluate whether the immunity activated by the Sinovac booster dose is able to recognise the new variant, Omicron.

According to Dr Kalergis, the subjects who were vaccinated with the booster dose of Sinovac possess T cells that are activated against the Omicron variant in a similar way to the original strain, indicating that the vaccine contains antigens that are shared with the Omicron variant.

He added that study results show that T lymphocytes when come in contact with the Omicron variant, are capable of producing gamma interferon which have potent virus killing ability.

“It is very likely that this partial recognition of the variants is contributing to the effectiveness of the vaccine at the population level, in the extent to which these variants have circulated in our country,” Dr Susan Bueno, UC Academic and Scientific director of the CoronaVac ScientificClinical Study in Chile, said in a recent statement.

“In fact, population data have shown that vaccines have worked to date to control the variants that have emerged.”

Meanwhile, the researchers in Chile are also preparing the study of the antibody response against the new variant in collaborative work between the Catholic University, the University of Chile, the La Jolla Institute of Immunology in California (US) and Sinovac in China.

The new deadly Omicron (B.1.1.529) Covid-19 Variant of Concern, identified in South Africa and also detected in Europe and Asia has raised concern worldwide given the number of mutations and reports that it might spread even faster and evade antibodies from prior infection of the virus or vaccination.