On Jun. 13, 2020, Sinovac Biotech announced positive preliminary results of phase I/II clinical trial for the Companyﾒs COVID-19 vaccine candidate, named CoronaVac, which showed favorable immunogenicity and safety profiles. The phase I/II clinical trials were designed as randomized, double-blind and placebo-controlled studies. In total, 743 healthy volunteers, aged from 18 to 59 years old, enrolled in the trials.