Mucosal Immunization

Immunization against infectious diseases is considered to be one of the most cost-effective public health interventions. Mucosal immunization may be defined as introducing a vaccine by the mucosal route in order to induce both mucosal and systemic immunity against a pathogen. Mucosal immune system is an integrated cross-communication pathway consisting of inductive sites where antigens are encountered and selectively taken up for the initiation of immune responses and effector sites where these immune responses are elicited. Thus the mucosal vaccines have the advantage of preventing colonization or infection of mucosal surfaces with a pathogen, as well as hindering the dissemination and systemic invasion of the pathogen. In addition to protecting the vaccinated individual, some of the mucosal vaccines may also have a herd effect through elimination of the transmission of pathogen between susceptible hosts. Further benefits of mucosal immunization are ease of administration, suitability for mass vaccinations, being more acceptable than the injection vaccines, and prevention of risky and unsafe injections. Although live oral polio vaccine, which has been widely used in Turkey for decade,s is a very good example of mucosal immunization, so far only a few mucosal vaccines have been licensed for human use. The development of new antigen delivery and adjuvant systems that can efficiently help to introduce vaccine antigens to the mucosal immune system are expected to revolutionize the field of mucosal vaccine production.