Mucosal immunization: a realistic alternative.

Most infections occur at or through mucosal surfaces. Despite this knowledge, current vaccination practices rely predominantly on parenteral administration with only a few vaccines being registered for administion by the mucosal route. Whilst mucosal immunization brings many advantages, the lack of reliable delivery systems has been a major drawback to date. With the recent advances in delivery system technology and the improved understanding of site specific mucosal immune mechanisms, mucosal immunization offers an exciting alternative vaccination strategy.