[A new combined vaccine against yellow fever and measles in infants aged 6 to 24 months in Mali].

In a rural area in Mali, 453 children were randomly enrolled in a study comparing the safety and the immunogenicity of a combined yellow-fever-measles freeze dried vaccine with each yellow-fever and measles separate administration. Children were divided in 2 populations 4-8 and 12-24 month old. 249 were controlled for measles (inhibition of hemagglutination) and yellow-fever (seroneutralization) antibodies. Seroconversion rates for measles were 82% when administrated before 9 months and 100% when given in 12-24 months period. Measles GMT is similar whatever the schedule or the age group; so, early vaccination does not impair the immunogenetic response. Moreover, 96% of the children vaccinated before 9 months still have detectable measles protective antibodies 8 months after. Among the initially seronegative children, the yellow-fever response is satisfactory with 92 to 96% seroconversion rate and post-immunization GMT ranging 16.5 to 29.5 without any statistical difference between the vaccine and age groups. The safety of the combined yellow-fever-measles vaccine is assessed by the rare number of reactions which are equivalent with the normally expected reactions with each vaccine administered separately. The results demonstrate the satisfactory immunogenicity and safety of the combined yellow-fever-measles vaccine. Combine yellow-fever-measles vaccination could help to improve the feasibility of EPI.