Bioreactor technologies for bacterial-based vaccine manufacturing and industrial scale-up: insights and future...

The production of bacterial-based vaccines depends fundamentally on advanced bioreactor technologies, which are continuously evolving to meet rising demands for efficiency, quality, and scalability. In this review, several key challenges that constrain the translational impact of bioreactor technologies for bacterial vaccines were identified. First, there is notable variability in bioreactor performance across different bacterial strains and vaccine targets, which undermines the generalizability of process designs. Second, the understanding of how scale-up affects yield, product quality, immunogenicity, and regulatory readiness remains incomplete. It limits confidence in translating lab-scale results to manufacturing environments. Third, real-time analytics and decision-support tools are not sufficiently integrated into control strategies. This leads to fragmented data-to-decision workflows. The review provides concrete, actionable directions to address these challenges. Emerging trends such as real-time monitoring, simulation tools, data-driven process intensification, and modular, single-use platforms are discussed for their potential to address these limitations. The optimized bioreactor design, precise operational control, and sustainable practices are emphasized. It is also illustrated how multidisciplinary collaborations can tailor bioreactor configurations to specific bacterial strains and vaccine targets that deliver reliable scalability.