Sinovac Biotech has announced the results of its preliminary study on whether its CoronaVac vaccine is effective against the Omicron variant. Sinovac had acquired two Omicron virus strains from Hong Kong and conducted neutralization tests. The positive rate of neutralizing antibodies produced was 94 percent in 48 samples inoculated with three doses of CoronaVac. Sinovac is running more studies to get a comprehensive evaluation of the impact of Omicron on the vaccine.