Singapore to Buy Covid Jab From China’s Sinovac Biotech Liao Shumin Singapore to Buy Covid Jab From China’s Sinovac Biotech (Yicai Global) Dec. 15 -- Singapore recently signed an advance purchase agreement with Chinese vaccine maker Sinovac Biotech for Covid-19 vaccines, Singapore’s Lianhe Zaobao reported yesterday, but without detailing the number of shots to be supplied. The Sinovac Biotech inoculants will arrive in batches next year, and Singapore is also in contact with other pharmaceutical companies, per the report. Beijing-based Sinovac Biotech is promoting Phase III clinical trials of its inactivated vaccine CoronaVac against Covid-19 in Brazil, Indonesia, Turkey and Chile. Indonesia's state-owned pharma firm PT Bio Farma said this month that CoronaVac has proven 97 percent effective in early trials, and its ultimate efficacy rate will be determined next month.