Covid-19: Sinovac booster dose can activate cellular immunity against Omicron variant, study suggests

KUALA LUMPUR: Preliminary results of a study conducted by the Pontifical Catholic University in Chile (UC) shows that the Covid-19 Sinovac vaccine booster dose could activate cellular immunity against the Omicron variant on subjects who were given two doses of the same vaccine previously.

The objective of the study led by Millennium Institute on Immunology and Immunotherapy director Prof Dr Alexis M. Kalergis, was to assess whether the immunity activated by the Sinovac vaccine booster dose was able to recognise the Omicron variant.

Dr Alexis, in a statement released by Pharmaniaga Saturday (Jan 1), said those who have received the Covid-19 Sinovac vaccine booster dose had T-cell levels that were activated against the Omicron variant in a similar way to the original strain.

"This shows that the vaccine contains antigens that are found in the Omicron variant. The results show that when T-lymphocytes come in contact with the Omicron variant, they are able to produce gamma interferon which is capable of killing the dangerous virus,” he said.

Meanwhile, UC’s Academic and Scientific director for the CoronaVac Scientific-Clinical Study in Chile, Dr Susan Bueno, said it was most likely that partial recognition of these variants had contributed to the effectiveness of the vaccine among the population, despite the variants being widespread in Chile.

"Population data shows that the Covid-19 Sinovac vaccine has worked well so far to control the variants that have emerged,” she said.

The statement also said researchers in Chile in collaboration with the Catholic University, the University of Chile, the La Jolla Institute for Immunology in California (USA) and Sinovac in China were also in the midst of conducting a study on the antibody response against the new variant.

The new Omicron (B.1.1.529) Covid-19 variant of concern (VoC), identified in South Africa and also detected in Europe and Asia, has raised concerns 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.

The Sinovac Covid-19 booster shot has recently been approved by the Drug Control Authority in Malaysia and is currently available in selected private healthcare facilities. - Bernama