Every year the growth of the poultry industry is severely threatened by a number of infectious viral, bacterial and parasitic diseases. There are a number of vaccines to control these diseases including inactivated virus vaccines, attenuated virus vaccines, live virus vaccines, and subunit vaccines, but they are often relatively expensive and require cold storage and trained people to administer them, especially in developing countries. Plant-based vaccines provide a better option to control these diseases in low profit margin poultry industry. Still there are some challenges in the field of plant-based, so called ‘green’ vaccines. Injection-based oral priming is a big challenge for commercialisation of green vaccines so, new techniques are needed in the field of plant-based vaccine to pass these barriers for commercialisation. This discusses the potential for plant-based vaccines and whether they are good option to control poultry diseases.

The benefits of using plant-based oral vaccines are discussed. Transgenic maize expressing an antigen of transmissible gastroenteritis virus (TGEV) is reported as a model to demonstrate efficacy. Young pigs that were fed the TGEV corn orally were protected against challenge with virulent TGEV. Additional parameters important in providing a reliable and consistent supply of plant-based vaccines are discussed. Finally, vaccines developed in maize are evaluated for their potential to contaminate either the food supply or the environment.