Phase IV Study of SINOVAC 23-Valent Pneumococcal Polysaccharide Vaccine Published in Vaccines

2025-09-01

BEIJING, September 1, 2025 – SINOVAC's 23-valent pneumococcal polysaccharide vaccine (PPSV23) induces a significant immune response and maintains a favorable safety profile in individuals aged two years and older, with performance comparable to internationally marketed vaccines, according to a Phase IV study published on August 15, 2025, in the peer-reviewed journal Vaccines.

The randomized, double-blind, active-controlled clinical trial, jointly conducted by the Shaanxi Provincial Center for Disease Control and Prevention, the National Institutes for Food and Drug Control (NIFDC), and Beijing Sinovac Biological Products Co., Ltd., evaluated 1,799 volunteers aged two years and older. Participants were randomized at a 2:1 ratio to receive either SINOVAC's PPSV23 or a licensed comparator vaccine to assess the immunogenicity and safety profiles.

Key Clinical Findings:

Non-inferior Immunogenicity: On day 30 post-vaccination, seroconversion ratesfor each of the 23 serotypes ranged from 59.22% to 95.67% in the SINOVACgroup, and in the control group from 59.66% to 94.07%. All 23 serotypesevaluated in the SINOVAC group met non-inferiority standards.
Enhanced Response: SINOVAC’s PPSV23 demonstrated enhanced immune response in 12 specificserotypes: 6B, 23F, 1, 2, 4, 8, 9N, 9V, 11A, 15B, 17F, and 18C.
ComparableSafety Profile: The incidence rate of adverse reactions within30 days post-vaccination was 19.68% for the SINOVAC group and 19.67% forthe control group, showing no statistically significant difference betweenthe two cohorts.

The findings supports that SINOVAC’s PPSV23 as a safe and effective immunogenic vaccination option for the prevention of pneumococcal diseases in individuals two years and older, including children, adults, and the elderly.

The full research paper, titled "Safety and Immunogenicity of a 23-Valent Pneumococcal Polysaccharide Vaccine (PPSV23) in Chinese Children, Adults and the Elderly: A Phase 4, Randomized, Double-Blind, Active-Controlled Clinical Trial", is available at: https://doi.org/10.3390/vaccines13080866.

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.