Plant molecular pharming is a promising system for cost-effective production of veterinary vaccines

Vaccination of animals has been used for centuries and is generally considered the most cost-effective and sustainable method of disease control and prevention. About twenty-five years ago, vaccines were in a inactive form or live attenuated organisms and often were not very effective. Advances in molecular biology and biotechnology have made it possible to develop new vaccines and therapeutic targes. Plant expression system has been demonstrated to be a promising platform for production of a variety of recombinant proteins such as vaccines, antibodies, therapeutic proteins, human and industrial enzymes, toxins etc. for health, agricultural and industrial applications. Although plant produced products are already available and licensed for human use, however, there are currently no plant-based vaccines on the market for animal use other than the Newcastle poultry vaccine. This is probably explained by relatively high cost of plant produced recombinant protein based vaccines for animal use. Therefore, the development of inexpensive and affordable plant-based vaccines and their formulation is very important for the production of economical animal vaccines. In this review, (1) different expression systems, (2) the history of plant-based expression systems, (3) different types of vaccines, and(4) plant-based animal vaccine production in plants are discussed. We also discussed the advantages of plants in the development of veterinary vaccines and new developed strategies that can lead to the production of cost-effective, stable and highly immunogenic veterinary vaccines.