Emerging Nanovaccine Technology: Defense Against Infection by Oral Administration

Oral vaccines have been proposed as a potential vaccine against a variety of infections, particularly invading pathogens throughout the GIT. Oral vaccinations targeting the large intestine could be a viable alternative to intracorneal immunizations which have been shown to be effective against rectogenital infections but are impractical during mass vaccination. Furthermore, the oral route allows for the development of humoral and cellular immune responses in both systemic and mucosal locations, resulting in a larger and longer-lasting protective effect. Oral administration, on the other hand, is difficult, needing formulations to overcome the harsh GI efficiency and reduce tolerance induction to obtain adequate protection. This review article will highlight the mode of action of oral vaccines, the list of license oral vaccine, type of vaccines, and the physiological barriers and immunological barriers to oral transport of peptides and proteins.