Vaccination techniques have developed rapidly over the last several decades from the immunization with live attenuated pathogens to the use of peptide and DNA subunit vaccines, from the use of classical adjuvants to cell-directed delivery. Vaccination techiques are also under investigation for the treatment of tumors and autoimmune diseases. However, profound knowledge of activation mechanisms of the immune cells on a molecular level is prerequisite for a better understanding of the immune response, and for the development of effective immunomodulatory tools. In this review we discuss the models of BCR and TCR activation, and using the example of some vacciantion technologies, we show, how the understanding of these models could help in the design of a new generation of vaccines.