The 4th International Workshop in Vaccine Adjuvants and Parasitic Vaccines (Adjuvant 2008), hosted by the Cuban Society for Immunology, attracted approximately 70 scientists from 22 countries. The meeting goal was mainly to share recent progress and discuss future challenges regarding vaccine adjuvants for the development of mucosal vaccines, as well as antiparasitic vaccines. Five keynote addresses, 21 oral presentations and 28 posters were presented, and the meeting was ended with a 'hot-topic' session discussing future challenges. This article highlights the most important issues discussed.