BEIJING: A third shot of the Sinovac Covid-19 vaccine administered six months or more after the second dose will give a remarkable boost to people’s immunity against the deadly virus, a new study has found.
The study was published on medrxiv.org for peer review.
Chinese researchers inoculated over 500 participants with a third dose six to eight months after their second jabs.
They found that the additional shot led to a significant increase in antibody levels, with geometric mean titres assessed 14 days later increasing to 137.9, or approximately three-fold.
The study also found that although neutralising antibody levels declined six months after two Sinovac shots, a two-dose schedule generated good immune memory.
The research was consistent with recent studies on booster immunisation with the AstraZeneca vaccine, which have showed higher concentrations of total antibodies after a third dose.
Experts in viral diseases and infectology have highlighted the efficacy of Chinese vaccines against Covid-19 and its new variants.
“According to the evidence available so far, vaccines that have been licensed by the World Health Organisation are effective against all variants in circulation globally,” said Jairo Mendez Rico, adviser on emerging viral diseases to the Pan American Health Organisation. — Xinhua