Dr. Weidong Yin has been Chief Executive Officer, President and Secretary at Sinovac Biotech Ltd. since September 24, 2003 and serves as its Managing Director. Dr. Yin serves as General Manager of Sinovac Biotech Co. Ltd. He serves as the President at Sinovac Biotech Co., Ltd. He is responsible for the State Model Project for Hi-tech Industrialization. He served as General Manager of Tangshan Yian Bioengineering Co., Ltd and served as a Medical Doctor in infectious disease at the China Center for Disease Control and Prevention, Tangshan City, Hebei Province. He served as the Chief Executive Officer, President and Secretary at Net Force Systems Inc. since September 24, 2003. He has devoted 20 years to the Hepatitis A virus research and is the technological inventor of Inactive Hepatitis A Vaccine. Dr. Yin is also heading the research on Inactivated SARS Vaccine. In addition, he was appointed to be the principal investigator by the Chinese Ministry of Science and Technology for many key governmental R&D programs such as 'Inactivated Hepatitis A vaccine R&D', 'Inactivated SARS vaccine R&D' and 'New Human Influenza Vaccine (H5N1) R&D'. He serves as the Chairman of the Board at Sinovac Hong Kong, Tangshan Yian and Sinovac Dalian. He serves as the Chairman of the Board at Sinovac Biotech Ltd. since September 2003 and has been its Director since September 24, 2003. Dr. Yin serves as Director of Sinovac Biotech Co. He served as a Director at Net Force Systems Inc. since September 24, 2003. He obtained his Masters degree in Business Administration from the Singapore State University. He obtained his MBA from the National University of Singapore and his medical degree from Tangshan Medical School.