Sinovac Announces Upsizing and Pricing of Common Share Offering

BEIJING, Jan. 28 /PRNewswire-Asia/ -- Sinovac Biotech Ltd. (Nasdaq: SVA) ("Sinovac" or the "Company"), a leading China-based vaccine manufacturer, announced today that it has priced its public offering of 10,000,000 common shares at $5.75 per common share. Sinovac has granted the underwriters a 30-day over-allotment option to purchase up to an additional 1,500,000 common shares on the same terms and conditions. This reflects an increase in the size of the offering from the previously announced offering of 8,650,000 common shares, plus underwriters' over-allotment option to purchase 1,297,500 common shares. The closing of the offering is subject to customary closing conditions and the common shares are expected to be delivered on February 2, 2010.

Sinovac will receive net proceeds of approximately $53.8 million, or $62.0 million if the underwriters exercise their over-allotment option in full, after deducting underwriting discounts and commissions and estimated offering expenses payable by the Company. Sinovac plans to use the net proceeds of the offering to fund the acquisition and expansion of production facilities, the enhancement of production lines, the research and development of product candidates, the expansion of product pipeline, and general corporate purposes (including an undetermined amount for potential acquisitions).

UBS Securities LLC and Piper Jaffray & Co. are serving as joint bookrunners for the offering.

The offering is being made under Sinovac's currently effective shelf registration statements on Form F-3 filed with the Securities and Exchange Commission on November 18, 2009 and January 27, 2010. This press release does not constitute an offer to sell, or the solicitation of an offer to buy, securities, and does not constitute an offer, solicitation or sale in any jurisdiction in which such offer, solicitation or sale would be unlawful.

Copies of the prospectus supplement and the accompanying prospectus relating to this offering may be obtained from UBS Securities LLC, Attention: Prospectus Department, 299 Park Avenue, New York, NY 10171, U.S.A., telephone: 888-827-7275, or Piper Jaffray & Co., Attention: Equity Capital Markets, 800 Nicollet Mall, Suite 800, Minneapolis MN 55402, U.S.A., telephone:

1-800-754-4781.

About Sinovac

Sinovac Biotech Ltd. is a China-based biopharmaceutical company that focuses on the research, development, manufacture and commercialization of vaccines that protect against infectious diseases. Sinovac's vaccine products include Healive(R) (hepatitis A), Bilive(R) (combined hepatitis A and B), and Anflu(R) (influenza). Panflu(R) and Panflu.1(TM), Sinovac's pandemic influenza vaccine (H5N1) and H1N1 vaccine, have already been approved for government stockpiling. Sinovac is developing vaccines for a number of different infectious diseases including enterovirus 71, pneumococcal disease, Japanese encephalitis, haemophilus influenzae type b (Hib), meningitis, rabies, chickenpox, mumps and rubella. Sinovac is also conducting field trials for independently developed inactivated animal rabies vaccine.

Safe Harbor Statement

This announcement contains forward-looking statements within the meaning of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. All statements other than statements of historical fact in this announcement are forward-looking statements. These forward-looking statements involve known and unknown risks and uncertainties and are based on current expectations, assumptions, estimates and projections about the Company and the industry in which the Company operates. The Company undertakes no obligation to update forward-looking statements to reflect subsequent occurring events or circumstances, or to changes in its expectations, except as may be required by law.

For further information, please contact:

Helen G. Yang

Sinovac Biotech Ltd.

Tel: +86-10-8289-0088 x 9871

Fax: +86-10-6296-6910

Email: info@sinovac.com

Investors:

Amy Glynn/Stephanie Carrington

The Ruth Group

Tel: +1-646-536-7023/7017

Email: aglynn@theruthgroup.com

scarrington@theruthgroup.com

Media:

Janine McCargo

The Ruth Group

Tel: +1-646-536-7033

Email: jmccargo@theruthgroup.com

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