Sinovac Biotech announces first sales of its seasonal influenza vaccine, Anflu Sinovac Biotech announced that the third product of the co, seasonal influenza vaccine, is successfully released for sale by National Institute for the Control of Pharmaceutical and Biological Products. On the same day, the first bunch of purchase orders is signed with several customers. These purchase orders represent a major step for the co as its third vaccine product begins sales in China. And it is expected to be another major source to generate sales revenue for the Company.