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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 global biopharmaceutical company headquartered in China. Guided by its mission to “Supply Vaccines to Eliminate Human Diseases,” the Company is dedicated to the research, development, manufacturing and supply of vaccines and related biological products, providing vaccine products and related solutions for disease prevention and control worldwide.
SINOVAC has a diversified vaccine portfolio across multiple disease areas, including influenza, viral hepatitis, varicella, hand, foot and mouth disease (HFMD), poliomyelitis, rabies, tetanus, and pneumococcal disease. Three of SINOVAC's vaccines have been prequalified by the World Health Organization: the inactivated hepatitis A vaccine Healive®, the Sabin-strain inactivated poliomyelitis vaccine (sIPV), and the live attenuated varicella vaccine.
SINOVAC has extensive experience in vaccine research, development and commercialization for emerging infectious diseases and public health emergencies. The Company initiated vaccine R&D in response to major public health threats, including SARS, H5N1, H1N1, and COVID-19, and developed the world's first inactivated SARS vaccine (with Phase I clinical trials completed), China's first inactivated pandemic influenza vaccine against H5N1 (Panflu®), the world's first H1N1 influenza vaccine (Panflu.1®), and CoronaVac®, the world's most widely used inactivated COVID-19 vaccine. Beyond its marketed portfolio, SINOVAC continues to advance its R&D pipeline, spanning combination vaccines, recombinant protein vaccines, mRNA technologies, antibody-based products, and other next-generation technologies and product platforms, while expanding its capabilities in disease prevention and biopharmaceuticals.
With a long-standing commitment to innovation and global health, SINOVAC continues to deepen collaboration with research institutions, international organizations, and local partners while expanding its global presence. Through technological collaboration, localized production, and industrial partnerships, the Company aims to improve access to high-quality vaccines across regions, better address local disease prevention and healthcare needs, and strengthen preparedness for future public health challenges.
For more information, please see the Company's website at www.sinovac.com.