Mucosal delivery of vaccine antigens and its advantages in pediatrics.

The delivery of vaccines through the mucosal route is very practical, non-invasive and efficacious for the induction of mucosal and systemic immune responses. Appropriately formulated mucosal vaccines can stimulate all arms of the immune system and could be exploited for protection against pathogens that infect the host through the mucosal surfaces as well as those acquired through other routes. There are few available mucosal vaccines so far and these are mainly based on whole microorganisms. The development of new generation mucosal vaccines based on purified protective antigens has been hampered for a long time by the low immunogenicity of soluble antigens and by the lack of safe and efficacious mucosal adjuvants. However, we have now several promising candidate adjuvants and delivery systems for mucosal immunization. In this review I will illustrate the advantages of mucosal vaccination and I will discuss what we still need to develop safe and efficacious mucosal vaccines that would be beneficial especially for young children.