[Better vaccinations - new approaches for targeted immunomodulation in healthy and immunosuppressed]

Infectious diseases are the main cause of mortality and morbidity worldwide. The development of successful vaccines is thus one of the major achievements in medical history and may have saved more lives than antibiotics. Whereas the first vaccines were developed in a rather empiric way, new insights into the immunological mechanisms of a successful vaccine response allow modifications of the generally used vaccination protocols and are a prerequisite for the generation of vaccines against new pathogens such as HIV, malaria, dengue virus and others. The aim of effective vaccine development is an avirulent, non-invasive, non-replicating vaccine, which induces long-lived, pathogen-specific immune responses. The addition of adjuvants, modifications of the dose, dose interval and application route can improve antibody-titers and cellular immune responses and thus improve vaccination outcome. On the other hand primary or secondary immunodeficiency leads to an increased susceptibility for infectious diseases and impaired immune responses to vaccinations. These patients should be vaccinated with dead vaccines, whereas live vaccines are generally contraindicated. Here we summarize current and future approaches to enhance vaccine induced immune responses and highlight some of the issues of vaccinations in immunosuppressed individuals.