Author(s): Doshi V, Rawal H, Mukherjee S
The idea of an edible vaccine is coming closer to reality as scientists have found a way to incorporate the protein gene with some antigen in some plants. The major hurdles in the path of an emerging vaccine technology are being overcome. In this context, genetically modified (GM) plants are being investigated for the production of vaccines, antibodies and therapeutic proteins. The development of GM crops to produce drugs and vaccines has received considerable investment and is relatively well advanced. The myth surrounding edible vaccines and 'food as pill' is the difficulty to control their intake and distribution, particularly in developing countries where education levels and literacy may be low. However, this concept suffers from the fact that the potency of this class of vaccines and drugs remains unmasked to the majority of the population, which has to be publicized and campaigned in a scientific manner, to make it realistic and useful for the common man. Creating edible vaccines involves introduction of selected desired genes into plants and then inducing these altered plants to manufacture the encoded proteins. This process is known as "transformation," and the altered plants are called "transgenic plants." Like conventional subunit vaccines, edible vaccines are composed of antigenic proteins and are devoid of pathogenic genes. Thus, they have no way of establishing infection, assuring its safety, especially in immuno-compromised patients. Conventional subunit vaccines are expensive and technology-intensive, need purification, require refrigeration and produce poor mucosal response. In contrast, edible vaccines would enhance compliance, especially in children and because of oral administration, would eliminate the need for trained medical personnel. Their production is highly efficient and can be easily scaled up. If the technology is properly nurtured and given the right direction, it may usher into a new era where we will be asked to take “food” rather than “drugs” when we are ill. This review attempts to discuss the current status and future of this new preventive modality.