By Fineline Cube 
China‑based Shenzhen Kangtai Biological Products Co., Ltd. (SHE: 300601) has entered the clinical stage with its newly‑developed quadrivalent influenza split‑virus vaccine, designed to protect children aged 6‑35 months. The company announced on Nov. 3 2025 that the first subject has been successfully enrolled, marking the official start of the Phase I trial.
Product Profile
- Vaccine type: Quadrivalent influenza split‑virus
- Target population: Infants 6 – 35 months
- Mechanism: Induces humoral immunity against four circulating flu strains, preventing influenza caused by vaccine‑matching viruses
- Delivery: Split‑virus formulation, administered via standard intramuscular injection
Influenza, an acute respiratory disease, remains a leading cause of morbidity in early infancy. Vaccination is regarded as the most cost‑effective preventive measure and forms a key component of public‑health strategies to curb outbreaks.
Phase I Trial Highlights
- Trial initiation – Official launch of the first‑in‑human safety and immunogenicity study.
- Enrollment milestone – First subject enrolled and dosed – a benchmark for progressing to subsequent phases.
- Regulatory context – Compliance with China’s national vaccine regulatory framework; aligns with the State Administration of Drug Administration (SDA) guidelines for infant vaccines.
Strategic Implications
- Portfolio diversification – Kangtai extends its vaccine catalog into the critical early‑infant segment, traditionally dominated by trivalent offerings.
- Market positioning – If clinical success continues, the quadrivalent product could capture a sizable share of China’s growing infant vaccine market, projected to reach USD 30 billion in 2025.
- Future outlook – Positive safety data will pave the way for Phase II/III studies and eventual commercialization, potentially unlocking reimbursement pathways with both public‑sector procurement and private‑payor systems.
Competitive Landscape
| Company | Vaccine Stage | Target Group |
|---|---|---|
| Kangtai Biological | Phase I | 6‑35 months |
| Beijing Institute of Medicine | Phase II | 6‑35 months |
| Novartis (Fluenz Tetra) | Commercial | 6‑35 months (US/Europe) |
Kangtai’s entry into the quadrivalent split‑virus niche offers a competitive edge by combining broader strain coverage with a proven split‑virus platform, potentially reducing the number of required dose‑es across seasons.
Bottom‑Line
The successful kickoff of a Phase I trial positions Shenzhen Kangtai Biological Products as a key player in China’s evolving vaccine ecosystem, with potential ripple effects across the infant influenza vaccine market.-Fineline Info & Tech