The authors first emphasize the efficiency and economic value of associated immunizations in developping countries. They report the first data collected in a campaign of immunization with a single injection of an extemporaneous mixture of antimeasles, antitetanus and antimeningococcal meningitis vaccines. This campaign took place in the Republic of Suddan from may 1976 to july 1977 and concerned 87 children. The specifications of each vaccine as well as the procedures of vaccination and serological control are given. The study of serological rates shows: -- a good response for measles with, in Africa, an optimal âge of 6 months and a new injection 6 months later; -- a low and late antibodies rise in tetanus with a good immunological memory giving way to an acute rise under a 2nd injection one year later; -- an immediate increase of the basic low rate of meningococcic antibodies existing in most Suddanese children before the injection. The authors consider the advantage of using also anti C meningococcal vaccine and to add an inactivated poliomyelitic vaccine. They give notice of the good stability in tropical environment of the vaccinal mixture they used.