[Immunological basics of vaccination].

Recent developments in research on infection and immunity change and extend the basic mechanisms underlying vaccination. Innate immunity is now known to recognize infectious organisms through pattern recognition receptors and this has implications for our understanding of the induction of immunity. It has become clear that successful defence of infections not only relies on antigen-specific activation of lymphocytes but also on stimulation of innate immunity. Such a concept helps to understand and develop new adjuvants. Furthermore, it is now shown that differentiation of T-cell immunity is far more complex than initially thought. New methods for measuring antigen-specific T-lymphocytes will help to reevaluate the role of T-cells in immune defence and protection on vaccination.