SVA [SINOVAC BIOTECH] CORRESP: 41st Floor, One Exchange Square 8 Connaught Place,
[41st Floor, One Exchange Square 8 Connaught Place, Central Hong Kong Tel: +852.2522.7886 Fax: +852.2522.7006 www.lw.com FIRM / AFFILIATE OFFICES Abu Dhabi Moscow Barcelona Munich Beijing New Jersey Brussels New York June 15, 2010 Chicago Orange County Doha Paris VIA EDGAR Dubai Riyadh Frankfurt Rome Jim B. Rosenberg, Senior Assistant Chief Hamburg San Diego Don Abbott, Senior Staff Accountant]