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SINOVAC Quadrivalent Influenza Vaccine Approved for Expanded Use From 6 Months of Age
BEIJING, Oct. 10, 2025 – SINOVAC's quadrivalent influenza vaccine, produced by its subsidiary Beijing Sinovac Biological Products Co., Ltd., has received approval from the National Medical Products Administration (NMPA) for an age expansion to include infants and young children aged 6 to 35 months. With this approval，the vaccine is now approved for all populations aged six months and older, providing a standardized 0.5ml dose across all age groups to simplify administration and improve vaccination accessibility in China.
Infants and young children aged 6–35 months are recognized as a higher-risk group for influenza-related complications. Vaccination is a widely accepted preventive measure to reduce the risk of influenza and associated complications. Household transmission is also considered an important contributor to influenza spread, and vaccination of eligible household members and caregivers is commonly recommended within public health guidance.
A Phase III clinical study evaluating the quadrivalent vaccine in infants aged 6 to 35 months demonstrated that a two-dose schedule (Days 0 and 28) of the 0.5mL formulation induced a superior immune response compared to two 0.25mL doses of a trivalent influenza vaccine. The study reported no significant difference in adverse reaction rates between the quadrivalent and trivalent groups, indicating that the increased antigen dosage did not elevate safety risks. Additionally, the incidence of adverse reactions after the second dose was lower than that of the first, suggesting favorable tolerability.
To date, SINOVAC's seasonal influenza vaccines have been widely used in nearly 20 countries and regions globally. The Company maintains international standards in manufacturing and quality control to ensure high immunogenicity and a favorable safety profile for its global vaccine supply.
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.