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SINOVAC's Varicella Vaccine Passes WHO Prequalification Reassessment
DALIAN, China, Dec. 17, 2025 – Sinovac Biotech Ltd. ("SINOVAC" or the "Company"), a leading provider of biopharmaceutical products in China, announced that the live attenuated varicella vaccine produced by its subsidiary, Sinovac (Dalian) Vaccine Technology Co., Ltd. ("Dalian SINOVAC"), has passed the World Health Organization (WHO) prequalification reassessment.
WHO prequalification is a dynamic and ongoing regulatory process rather than a one-time approval. The recent on-site review marked the first comprehensive reassessment of SINOVAC's live attenuated varicella vaccine since it first received WHO prequalification in November 2022.
An international inspection team of experts from the WHO conducted a systematic, comprehensive, and rigorous review of Sinovac Dalian's quality management system, production facility design and maintenance, and product lifecycle management. The team highly recognized Dalian SINOVAC's overall operational capability, noting that its quality management system is well-structured and effectively implemented, and that its high level of digitalization supports effective monitoring and continuous improvement throughout the manufacturing process.
Through on-site inspection and documentation review, the WHO team conducted a thorough assessment of Dalian SINOVAC's operations, focusing on the implementation of its quality management system, facility management, and the standardization of vaccine production processes. The team recognized the company’s disciplined management practices and consistent, reliable manufacturing capability.
The reassessment team also gave high marks to Dalian SINOVAC's sterile manufacturing management, noting that its production environment was well controlled and that critical manufacturing steps were subject to rigorous oversight, ensuring the safety and reliability of vaccine production. The team further observed that international quality principles and standards had been effectively implemented, reflecting the level of professionalism expected of a globally oriented vaccine manufacturer. Dalian SINOVAC’s varicella vaccine is produced throughout the full manufacturing process in a B+A cleanroom environment, making it the only varicella vaccine in China manufactured under this standard across the entire process. This helps minimize contamination risk and enhance product quality.
To date, three SINOVAC vaccines—the inactivated hepatitis A vaccine (Healive®), the live attenuated varicella vaccine, and the Sabin strain inactivated poliovirus vaccine—have received WHO prequalification. Among them, SINOVAC's varicella vaccine is the first and only varicella vaccine developed and manufactured in China to receive WHO prequalification. It has been distributed to nearly 20 countries and regions worldwide, with cumulative supply exceeding 20 million doses.
About SINOVAC
Sinovac Biotech Ltd. (SINOVAC) is a China-based global biopharmaceutical company, with a mission of "supply vaccines to eliminate human diseases", the company specializes in the research, development, manufacturing and commercialization of vaccines and related biological products that protect against human infectious diseases.
The company's diversified portfolio includes vaccines for influenza, viral hepatitis, varicella, Hand-Foot-Mouth disease (HFMD), poliomyelitis, pneumococcal disease, etc., of which 3 vaccines have been prequalified by WHO, including inactivated hepatitis A vaccine Healive®, Sabin-strain inactivated polio vaccine (sIPV), and varicella vaccine.
SINOVAC has a leading edge in developing vaccines to combat infectious disease outbreaks and was among the first to initiate R&D during major public health emergencies, including SARS, H5N1, H1N1, and COVID-19. The company developed the world's first inactivated SARS vaccine (Phase I completed), China's first H5N1 influenza vaccine (Panflu®), the world's first H1N1 influenza vaccine (Panflu.1®), and CoronaVac®, the most widely used inactivated COVID-19 vaccine globally.
Beyond its marketed portfolio, the company is advancing a robust pipeline that includes combination vaccines,recombinant protein vaccines and next-generation platforms such as mRNA technologies and antibodies.
With a long-standing commitment to innovation and global health, SINOVAC is expanding its global footprint by strengthening partnerships with research institutions, international organizations, and local partners. Through broader market presence, technological cooperation, and localized production, the company aims to accelerate vaccine development and supply, enhance regional access to high-quality products, and better address unmet medical needs while improving preparedness for future pandemics.
For more information, please see the Company’s website at www.sinovac.com.