Food-Grade Organisms as Vaccine Biofactories and Oral Delivery Vehicles

The use of food-grade organisms as recombinant vaccine expression hosts and delivery vehicles has been explored during the past 25 years, opening new avenues for vaccinology. Considering that oral immunization is a beneficial approach in terms of costs, patient comfort, and protection of mucosal tissues, the use of food-grade organisms can lead to highly advantageous vaccines in terms of costs, easy administration, and safety. The organisms currently used for this purpose are bacteria (Lactobacillus and Bacillus), yeasts, algae, plants, and insect species. Herein, a comparative and updated scenario on the production of oral vaccines in food-grade organisms is provided and placed in perspective. The status of clinical evaluations and the adoption of this technology by the industry are highlighted.