The rise of oral vaccines in modern healthcare- An emergence of paradigm shifting

The administration of vaccines stands as one of the most impactful prophylactic measures against infectious diseases for safeguarding global serenity. Although oral administration of vaccines is the most preferred route over parenteral administration, it represents a gold standard owing to its high patient compliance. Oral vaccines often encounter denaturation problems due to low gastric pH, decomposition by intestinal proteolytic enzymes, and barriers to reaching Gut-associated lymphoid tissues (GALT) to provoke efficient immune responses. The present review unveiled various approaches associated with the development of oral vaccines, numerous challenges manifested over their oral administration, followed by strategic overcoming via the adoption of specific adjuvants and nanocarriers (for immunomodulation and preservation of antigen).