SINOVAC's CoronaVac Used on Child Population in China, Good Antibody Levels Observed After Three Months Following Vaccination

SINOVAC's CoronaVac Used on Child Population

in China, Good Antibody Levels Observed After Three Months Following Vaccination

China, July 19, 2021 -- SINOVAC Biotech Ltd. (NASDAQ: SVA) ("SINOVAC" or the "Company"), a leading provider

of biopharmaceutical products in China, today announced CoronaVac, SINOVAC's COVID-19 vaccine, has started being used among

the child population in China.

study on immune persistency was conducted in 180 volunteers in a phase II clinical study on a group of participants ranging from

3 to 17 years of age. The results showed that, three months after two doses of the vaccine, the seroconversion rates for children and

adolescents were 98.9% and 100%, respectively. The geometric mean titer (GMT) of neutralizing antibody was close to the level recorded

at 28 days after vaccination and remained significantly higher than the level recorded in adults and elderly at 28 days after vaccination. This

indicates that CoronaVac has stable and good immunogenicity among the pediatric and adolescent population, recording better results compared

to those in people aged 18 and above.

was approved for emergency use on May 28, 2021 in China. SINOVAC's COVID-19 vaccine had also been filed for use in Indonesia

and was approved for use in the population of 12 to 17 years of age by Indonesian authorities in June 2021.

Lancet Infectious Diseases has published results from the Phase I/II clinical trials of an inactivated COVID-19 vaccine

developed by SINOVAC, also known as CoronaVac , in healthy children aged 3 to 17 years of age in China.

Biotech Ltd. is a China-based biopharmaceutical company that focuses on the research, development, manufacturing and commercialization

of vaccines that protect against human infectious diseases. SINOVAC's product portfolio includes vaccines against COVID-19, enterovirus71

(EV71), hepatitis A and B, seasonal influenza, 23-Valent pneumococcal polysaccharide ("PPV"), H5N1 pandemic influenza (avian

flu), H1N1 influenza (swine flu), varicella and mumps. SINOVAC's COVID-19 vaccine, CoronaVac , has been granted emergency use

approval or conditional marketing authorization by over 50 countries or regions worldwide. Healive , the hepatitis A vaccine manufactured

by the Company, has passed the assessment under WHO prequalification procedures in 2017. The EV71 vaccine, an innovative vaccine developed

by SINOVAC against hand foot and mouth disease caused by EV71, was commercialized in China in 2016. In 2009, SINOVAC was the first company

worldwide to receive approval for its H1N1 influenza vaccine, which it has supplied to the Chinese Government's vaccination campaign and

stockpiling program. The Company is also the only supplier of the H5N1 pandemic influenza vaccine to the government stockpiling program.

In 2021, SINOVAC's Sabin-strain inactivated polio vaccine has approved for registration. The Company is developing several new products

including combined vaccines. SINOVAC primarily sells its vaccines in China, while also exploring growth opportunities in international

markets. The Company is seeking market authorization of its products in over 30 countries outside of China. For more information, please

see the Company's website at www.sinovac.com.

Safe Harbor Statement

This press release may include certain statements

that are not descriptions of historical facts, but are 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 terminology

such as "will," "expects," "anticipates," "future," "intends," "plans,"

"believes," "estimates" and similar statements. Forward-looking statements involve risks, uncertainties and other

factors that could cause actual results to differ materially from those contained in any such statements. In particular, the outcome of

any litigation is uncertain, and the Company cannot predict the potential results of the litigation it filed or filed against it by others.

Additionally, the triggering of a shareholder rights plan is nearly unprecedented, and the Company cannot predict the impact on the Company

or its stock price as a result of the trigger of the rights plan.

Tel: +86-10-8279-9871 or

Fax: +86-10-6296-6910

Email: ir@sinovac.com

U.S.: 1-646-308-1707

Email: william.zima@icrinc.com