Sinovac Initiates Phase II Volunteer Enrollment For Split Viron Pandemic Influenza (H5N1) Vaccine

Sinovac Biotech Ltd. (Amex:
SVA), a leading provider of vaccines in China, announced the
initiation of volunteer enrollment in its Phase II clinical trial for its
split pandemic influenza vaccine. The preliminary results from this study
are expected to be available in early 2009.



The randomized and double-blind trial is expected to enroll 210
adolescents, between the ages of 12 to 17, who will receive doses of 10ug,
15ug or 30ug, and 140 children, between the ages of 3 to 11, who will
receive doses of 10ug or 15ug. Volunteers will be followed for two months
with safety and immunogenicity data collected for the assessment of the
vaccine.



Mr. Weidong Yin, Chairman, President and CEO, commented, ''Split
influenza vaccine is believed to cause less adverse reactions in children
compared to whole-viron influenza vaccine. Sinovac's split pandemic
influenza vaccine aims at protecting the pediatric and adolescent
population. Based on the positive safety results of the Phase I trial, the
Phase II study will be conducted to further collect the vaccine's safety
data in children and adolescents, as well as assessing the immunogenicity
of different doses.''



Sinovac received approval from the China State Food and Drug
Administration (SFDA) in April 2007 to conduct clinical trials for two
types of the H5N1 vaccine, namely Phase Ib and II trials of the H5N1 whole
viron vaccine and Phase I and Phase II trials of the H5N1 split vaccine. In
December 2007, Sinovac reported positive top-line results from the
completed Phase II clinical trial of Panflu(TM), its pandemic influenza
(H5N1) whole viron inactivated vaccine. In April 2008, Panflu(TM) was
granted a production license by the China State Food and Drug
Administration (SFDA). Panflu(TM) is the first and only approved vaccine
available in China against the H5N1 influenza virus.



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 human infectious diseases. Sinovac's
commercialized vaccines include Healive(R) (hepatitis A), Bilive(R)
(combined hepatitis A and B), Anflu(R) (influenza) and Panflu(TM) (H5N1).
Sinovac is currently developing Universal Pandemic Influenza vaccine and
Japanese encephalitis vaccine. Additional information about Sinovac is
available on its website, sinovac.



Safe Harbor Statement



This announcement contains forward-looking statements. These statements
are made under the "safe harbor" provisions of the U.S. Private Securities
Litigation Reform Act of 1995. These forward-looking statements can be
identified by words or phrases such as "will," "expects," "anticipates,"
"future," "intends," "plans," "believes," "estimates" and similar
statements. Among other things, the business outlook and quotations from
management in this press release contain forward-looking statements.
Statements that are not historical facts, including statements about
Sinovac's beliefs and expectations, are forward-looking statements.
Forward-looking statements involve inherent risks and uncertainties. A
number of important factors could cause actual results to differ materially
from those contained in any forward-looking statement. Sinovac does not
undertake any obligation to update any forward-looking statement, except as
required under applicable law.


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