OPTIMIZATION OF VERO CELL EXPANSION AND FLAVIVIRUS ANTIGEN PRODUCTION IN A BIOREACTOR USING SERUM-FREE MEDIUM

Japanese Encephalitis (JE) remains a significant global public health challenge in Asia, necessitating the development of efficient and scalable vaccine production methods. Traditional vaccine manufacturing often relies on serum-containing media and static culture systems, which pose risks of contamination and limited scalability. Vero cells are widely accepted mammalian cell lines used in research and commercial applications, particularly for vaccine production in both human and veterinary medicine(s). This article presents a refined methodology using serum-free media and microcarrier-based Vero cell bioreactor systems to enhance the productivity and safety of the SA 14-14-2 JEV strain. By employing Vero cells cultivated on Cytodex-1 microcarriers within a 3L bioreactor and utilizing serum-free media (VP-SFM and Cellin-1), we established a robust platform for high-titer vaccine manufacturing. Comparative analysis between static (CS-10) and suspension bioreactor cultures revealed that the bioreactor system significantly enhanced cell yields by approximately 30% (2.69 × 105 cells/cm². Furthermore, viral titers in the bioreactor reached 2.20 x 107 PFU/mL, representing a 10–15% increase over static conditions. These findings provide a standardized framework for industrial-scale, serum-free production of JE vaccines with improved efficiency and quality control. This optimised upstream process offers a scalable, safer, and more cost-effective platform for manufacturing flavivirus vaccines, thereby improving global access and pandemic preparedness.