Plant-Based Recombinant Vaccines for Foot-and-Mouth Disease: A Meta-Synthesis.

Background: Foot-and-Mouth Disease (FMD) remains a persistent global threat to livestock health and food security, particularly in endemic and resource-constrained regions. Conventional inactivated vaccines pose several challenges-including biosafety risks and dependence on cold-chain logistics. These limitations have prompted growing interest in plant-based recombinant vaccine platforms as innovative, scalable, and safer alternatives for FMD prevention. Methods: This study employed a qualitative meta-synthesis approach, guided by the Barroso-Sandelowski method, to systematically extract, interpret, and integrate findings from 35 peer-reviewed empirical studies published between 2000 and 2025. The selected studies focused on the development and evaluation of plant-made vaccines targeting FMD. Thematic coding and interpretive synthesis were applied to identify recurrent patterns, challenges, and opportunities across the literature. Results: The analysis yielded four dominant themes: (1) Platform Diversity: A variety of plant and algal expression hosts were used through transient or stable transformation systems, (2) Immunization Routes: Oral vaccination was noted for its logistical advantages and potential for mass immunization, though often requiring adjuvants to enhance immunogenicity, (3) Scale-Up Challenges: Key barriers included low recombinant protein yields, heterogeneity in post-translational modifications and high variability between production batches and (4) Regulatory Readiness: Despite encouraging pre-clinical data, most candidates have not progressed beyond experimental stages. Conclusion: Plant-based recombinant vaccines represent a promising frontier in the fight against FMD, offering novel avenues for safer, more accessible immunization strategies. However, their transition from bench to field remains hindered by technical limitations in expression and purification, as well as institutional and regulatory gaps.