SANTIAGO, March 16 — China-based Sinovac Biotech Ltd’s Covid-19 vaccine was 38.2 per cent effective in preventing infections during the Omicron wave in children aged three to five years, a study in Chile showed.

The study, published yesterday, has not yet been peer reviewed.

The findings are in contrast to earlier studies that showed the vaccine, CoronaVac, was 74.5 per cent effective in preventing infections in children aged 6 to 16 years, when Delta was the dominant variant.

Countries are increasingly recommending booster doses in the face of the circulating Omicron variant, which the World Health Organisation has said can bypass some protection imparted by vaccines. Most vaccines are still effective against severe infections.

Sinovac’s vaccine was 64.6 per cent effective in preventing hospitalisations and 69 per cent effective in preventing Covid-19 related ICU admissions, the Chilean study also showed.

A study by New York State researchers in February showed that Pfizer Inc’s vaccine quickly lost most of its ability to prevent infections in children aged 5 to 11 during an Omicron-led wave. — Reuters