SINOVAC Approved to Initiate Clinical Trial for Its Omicron Containing COVID-19 Vaccine in Chile

September 6, 2022, Beijing -- Sinovac Biotech Ltd. ("SINOVAC" or the "Company") (NASDAQ: SVA), a leading provider of biopharmaceutical products in China, announced that the Chilean Public Health Institute (Instituto de Salud Pública, ISP) approved a phase II clinical trial for its inactivated Omicron strain COVID-19 vaccine and trivalent COVID-19 vaccine (ancestral, Delta and Omicron variants) on August 31st. The clinical trial will evaluate the immunogenicity and safety of one booster dose of the two candidate vaccines in adults who had received two booster doses of CoronaVac^®, mRNA, or adenovirus vector COVID-19 vaccine. This study is the world's first study researching multivalent inactivated COVID-19 vaccine.

In this phase II randomized, double-blind, multicenter clinical trial,  826 fully vaccinated adults will be recruited. Participants belonging to the heterologous scheme are individuals who had received two CoronaVac^® doses, and two boosters of mRNA-based or viral vector-based vaccines, while participants of the homologous scheme had received four doses of CoronaVac^®. Individuals from the heterologous scheme will randomly receive a booster dose with the Omicron, Trivalent, or CoronaVac^® vaccines, while individuals from the homogeneous group will randomly receive a booster dose of the Omicron or the trivalent vaccines.

Mr. Weidong Yin, the Chairman, President, and CEO of SINOVAC said, "SINOVAC has made great progress collaborating with global partners in the development and manufacturing of the COVID-19 vaccine. We are proud of the fact that CoronaVac^® can protect individuals as young as 6 months of age and this clinical approval will allow even better vaccine protection."

About SINOVAC

Sinovac Biotech Ltd., (SINOVAC) is a China-based biopharmaceutical company that focuses on the R&D, manufacturing, and commercialization of vaccines that protect against human infectious diseases. SINOVAC's product portfolio includes vaccines against COVID-19, enterovirus 71 (EV71) infected Hand-Foot-Mouth disease (HFMD), hepatitis A and B, seasonal influenza, pneumococcal disease, H5N1 pandemic influenza (avian flu), H1N1 influenza (swine flu), varicella, mumps, and poliomyelitis. Its COVID-19 vaccine, CoronaVac^®, has been approved for use in more than 60 countries and regions worldwide. Its Healive^®, hepatitis A vaccine, passed WHO prequalification requirements in 2017. Its EV71 vaccine, Inlive^®, is an innovative vaccine commercialized in China in 2016. In 2022, SINOVAC's Sabin-strain inactivated polio vaccine (sIPV) was prequalified by the WHO.

SINOVAC was the first company to be granted approval for its H1N1 influenza vaccine Panflu.1^®, which has supplied the Chinese government's vaccination campaign and stockpiling program. The Company is also the only supplier of the H5N1 pandemic influenza vaccine, Panflu^®, to the Chinese government stockpiling program.

SINOVAC continually dedicates itself to new vaccine R&D, with more combination vaccine products in its pipeline, and constantly explores global market opportunities. SINOVAC plans to conduct more extensive and in-depth trade and cooperation with additional countries, and business and industry organizations.

For more information, please see the Company's website at www.sinovac.com.

Contact:

Sinovac Biotech Ltd.

PR Team

pr@sinovac.com

ICR Inc.

Bill Zima

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

william.zima@icrinc.com