[Sinovac Schedules 2010 Annual Meeting of Shareholders Beijing — June 18, 2010 — Sinovac Biotech Ltd. (Nasdaq: SVA), a leading developer and provider of vaccines in China, announced today that it will hold its 2010 Annual Meeting of Shareholders on Thursday, July 15, 2010 at 9:00 a.m. Beijing Time. The meeting will be held concurrently at No. 39 Shangdi Xi] [June 1 , 20 10 Dear Shareholder: You are cordially invited to attend the 20 10 annual meeting of shareholders of Sinovac Biotech Ltd. to be held on July 15, 2010 , at 9 : 00 A .M. Beijing time, at No. 39 Shangdi Xi Road, Haidian District, Beijing 100085, People’s Republic of China, and at the corresponding time in] [SINOVAC BIOTECH LTD. ( Incorporated in Antigua and Barbuda with limited liability) ( NASDAQ Ticker: SVA) FORM OF PROXY FOR 20 10 ANNUAL SHAREHOLDERS MEETING (AND ANY ADJOURNMENT THEREOF) (Note 1) I/We, 10 (Note 2) Annual Shareholders Meeting 10 Annual Shareholders meeting of the Company to be held on July 1 5 , 20 10 at 9:00 A.M. Beijing time] [1 -32371 SINOVAC BIOTECH LTD. No. 39 Shangdi Xi Road Haidian District Beijing 100085, People’s Republic of China Form 20-F x Form 40-F o o o SINOVAC BIOTECH LTD.]