Plant Edible Vaccines: A Revolution in Vaccination

Plants have been used as a source for many pharmaceutical since long. However, utilization of plant systems for production of edible vaccines has been a comparatively recent phenomenon. There are several potential advantages of plant derived vaccines over other conventional systems of vaccine production such as mammalian or avian cell culture. The cost of vaccines is one factor preventing further use of vaccination, leaving hundreds of thousands of children susceptible to preventable diseases. Especially for developing world this novel technique proved to be a boon for its low cost of production, convenient administration, easy storage and negligible chances of infection whereas the conventional system of vaccine production limits the applicability of vaccines in many parts of the world. These vaccines are prepared by introducing selected desired genes into plants and inducing these genetically modified plants to manufacture the encoded proteins. Transgenic plants may provide an ideal expression system, in which transgenic plant material can be fed directly as oral dose of recombinant vaccines. Expression of vaccines in plant tissue eliminates the risk of contamination with animal pathogen, provides a heat stable environment and enables oral delivery thus eliminating infection related hazards. Identification of transgenic material, containment of the transgenes and control of recombinant protein may be potential problems for large scale production of vaccines in plants. Factors like scaling up production as well as distribution and handling of transgenic plant material must comprise the future consideration in this field.