Sinovac Reports Preliminary Top-Line Results from Phase III Clinical Trial for EV71 Vaccine Candidate Against Hand, Foot and

Sinovac Reports Preliminary Top-Line Results from Phase III Clinical Trial for
         EV71 Vaccine Candidate Against Hand, Foot and Mouth Disease

- Unblinded Phase III Preliminary Results Demonstrate Vaccine Efficacy Rate of

PR Newswire

BEIJING, March 14, 2013

BEIJING, March 14, 2013 /PRNewswire/ --Sinovac Biotech Ltd. (NASDAQ: SVA), a
leading provider of vaccines in China, announced today preliminary top-line
data from its Phase III clinical trial assessing the efficacy, immunogenicity
and safety of the Company's proprietary Enterovirus 71 ("EV71") vaccine
against hand, foot and mouth disease ("HFMD").

The primary objective of the study was to evaluate the efficacy of the EV71
vaccine in the prevention of HFMD caused by EV71 in infants of 6 to 35 months
old.The preliminary Phase III data showed that Sinovac's EV71 vaccine was
95.4% (95% CI: 87.5%, 98.3%) efficacious against HFMD caused by EV71.

The Phase III trial showed good immunogenicity and safety for Sinovac's EV71
vaccine. The overall incidence of serious adverse events in this trial was
2.2% among the EV71 candidate vaccine recipients and 2.6% among those
receiving a control vaccine during the fourteen months observation period. The
difference in rates of serious adverse events ("SAEs") is not statistically
significant. Most of the SAEs were considered unlikely to be vaccine-related.

The double-blinded, randomized, placebo controlled Phase III clinical trial
was conducted at three sites across China's Jiangsu province.Approximately
10,000 healthy infants completed the two dose vaccination schedule (at 0 and
28 days) in the first quarter of 2012, prior to the HFMD epidemic season in
China, followed by active monitoring period.

In parallel, Sinovac conducted another clinical study that was comprised of
1,400 volunteers and designed to evaluate the consistency of three consecutive
lots of EV71 vaccine manufactured by the Company. The trial was conducted in
children from 6 month to 5 years old. After receiving the vaccine, the ratios
of neutralizing antibody GMTs on the 56th day of any two groups were
calculated and the 95% confidence intervals of the ratios are all between 0.67
and1.5, which indicates the immunogenicity of the three vaccine lots is
equivalent. The study results showed consistent immune response for all three
lots and a good safety profile.With immunogenicity equivalent across the
three consecutive lots, the results showed Sinovac's vaccine production
process and quality are stable.

In March 2008, an EV71 outbreak in Fuyang City of China's Anhui Province
caused 23 fatalities, and attracted significant attention from the government
and medical communities. In May 2008, the PRC Ministry of Health identified
EV71 as a Class C infectious disease according to prevention and control
regulations. EV71 outbreaks have increased over the last five years, with over
1 million cases identified and 500 to 900 reported fatalities each year.

Dr. Weidong Yin, Chairman, President and CEO of Sinovac, commented, "We are
excited to report an over 95% efficacy rate from the Phase III trial on our
proprietary EV71 vaccine candidate. The conclusion of this trial marks an
important milestone in the development of our proprietary vaccine. Hand, foot,
and mouth disease continues to represent a significant unmet public health
need and economic burden in China, as well as several other Asian countries.
Our EV71 vaccine is poised to provide an effective solution to prevent hand,
food and mouth disease caused by EV71, a much needed resource given the
current limited prevention and EV71 specific treatment methods. At Sinovac, we
are committed to our stated mission to develop and supply vaccines to
eliminate human diseases."

Professor Hua Wang, Lead Principal Investigator, stated, "The Phase III study
for Sinovac's EV71 vaccine candidate met its primary objective. The trial
results demonstrated that the vaccine is not only safe, but shows significant
efficacy in subjects."

The Company's next step is to finalize the clinical report, which will become
an important part of documents to be filed with the PRC State Food and Drug
Administration ("SFDA") for the application of new drug certificate, GMP
certification, and the production license in order to commence the commercial
production of the vaccine. In parallel, Sinovac's dedicated EV71 vaccine
manufacturing facility has been completed and is ready for the GMP inspection
by SFDA.

Sinovac obtained clinical research approval for its proprietary EV71 vaccine
candidate from the SFDA in December 2010, and completed Phase I and II
clinical trials in 2011. The preliminary results of the Phase I and Phase II
studies confirmed that Sinovac's vaccine candidate has good safety and
immunogenicity profile.

About Sinovac

Sinovac Biotech Ltd. is a China-based biopharmaceutical company that focuses
on research, development, manufacturing and commercialization of vaccines that
protect against human infectious diseases including hepatitis A and B,
seasonal influenza, H5N1 pandemic influenza and mumps, as well as animal
rabies vaccine.In 2009, Sinovac was the first company worldwide to receive
approval for its H1N1 influenza vaccine, Panflu.1, and has manufactured it for
the Chinese Central Government, pursuant to the government-stockpiling
program.The Company is also the only supplier of the H5N1 pandemic influenza
vaccine to the government-stockpiling program. Sinovac is developing a number
of new pipeline vaccines including vaccines for enterovirus 71 (against hand,
foot, and mouth disease), pneumococcal conjugate, pneumococcal
polysaccharides, varicella and rubella.Sinovac sells its vaccines mainly in
China and exports selected vaccines to Mongolia, Nepal, and the Philippines.

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.

Helen Yang
Sinovac Biotech Ltd.
Tel: +86-10-8279-9871
Fax: +86-10-6296-6910


Stephanie Carrington
The Ruth Group
Tel: +1-646-536-7017


Aaron Estrada
The Ruth Group
Tel: +1-646-536-7028

SOURCE Sinovac Biotech Ltd.

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