In 2004, the most important changes have been the necessity of adapting our vaccine strategies to the persistent risk of measles in Switzerland (infant immunization, catch-up until 40 years of age) and a better identification of those at high risk of infectious disease complications. This includes a first definition of those at high risk of complications from chickenpox, to which adolescents and young adults without a positive history of chicken-pox will be added in 2005. Certain "old vaccines" have been replaced by novel formulations. And new clinical studies have again contributed to provide the data needed to meet the expectations of some worried patients. What did not change in 2004 ? The Internet address allowing physicians to send any question related to vaccination: www.infovac.ch