Stability of a soybean seed-derived vaccine antigen following long-term storage, processing and transport in the absence of a cold chain

BACKGROUND: Soybean seeds are rich in natural protein and are favorable environments for targeted protein expression. Soybeans represent an ideal platform for the production of novel vaccines that, in theory, do not require a cold chain. This study investigated the stability of a soybean-derived antigen following long-term storage, formulation, and shipment overseas in the absence of refrigeration. RESULTS: Transgenic seeds can be stored for more than 4 years at ambient temperature with no detectable loss of FanC antigen stability. Conventional processing methods utilizing heat, mechanical extraction and solvent extraction resulted in practical formulations that could be lyophilized, stored as dried milk powder and rehydrated in water without loss of FanC antigen stability. Overseas shipment of transgenic seed powder and soymilk formulations in the absence of a cold chain had no adverse effects on formulations or the FanC antigen. CONCLUSION: The feasibility of long-term storage, processing and shipment of transgenic soy products in the absence of a cold chain was demonstrated. Soybeans represent a practical platform for development of novel vaccines to potentially address the worldwide need for vaccines that are cost-effective, easy to formulate and can be manufactured, stored and transported without refrigeration. (C) 2009 Society of Chemical Industry