[Conjugate vaccines].

Conjugate vaccines extend the vaccinal prevention for children to more diseases. Conjugating the capsular polysaccharide to a carrier protein transforms a T-independent antigen in a T-dependent, allowing protection of the children (before 2 years of age) against Haemophilus influenzae type b, meningococcal C and pneumococcal infections. This article reviews the 3 conjugate vaccines and their results with focus on some questions: antigens interference in the immunological response, serological subrogate for protection, herd immunity and replacement of circulating serotypes.