Mucosal immunization

Increased immunization coverage, along with improved sanitization and safe water, is the most important public health intervention to improve child health in documented human history, resulting in a significant decrease in child mortality during the 20 century. Immunization is considered by the World Health Organization (WHO) as one of the most cost-effective of all health interventions, having the capacity to not only save but also to transform lives from the misery of infectious diseases. Since 1988, polio has been eradicated in 121 countries and is today endemic in only four countries. Despite the many achievements of vaccines in reducing the burden of disease, many infectious diseases remain endemic in large parts of the world, in particular, in developing countries as well as in many indigenous communities and areas of low socio-economic status within developed nations. There are two key aspects that need to be addressed for any vaccination to be successful: first, to increase the potential to generate a potent defence against diseases that evade the immune system, and secondly, to induce long lasting protective immunity following a single administration. Consequently, the development of vaccines has always been focused on effective induction of both humoral and cell-mediated immunity (CMI). Most of the vaccines that are used today are delivered by intramuscular or