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Background: To improve measles control in Kinshasa, Zaire, a project to increase vaccine coverage was begun in 1988, and in 1989, the city vaccination programme changed measles vaccination policy from Schwartz vaccine at age 9 months to medium titre Edmonston Zagreb (EZ) vaccine at age 6 months. We report the impact of the programme on measles incidence and mortality., Methods: Data on vaccine coverage were obtained from cluster sample surveys conducted every 1-2 years and from routine reports of vaccine doses administered. Data on measles incidence and mortality were obtained from sentinel surveillance sites. The serological response to EZ measles vaccine was evaluated at a health centre in 1989 and in a community survey in 1990., Results: Measles vaccine coverage estimated in cluster surveys increased from 50% of the 1984 birth cohort to 89% of the 1989 birth cohort, accepting either a home-based record or a verbal history of vaccination. Reported measles incidence per 10,000 [corrected] population decreased by over 90%, from 37.5 in 1980 (early vaccination years) to 1.6 in 1991. There was a relative decrease in the proportion of cases aged < 9 months (32% of cases in 1986-1987 and 23% of cases in 1990-1991) and an increase in the proportion aged > 23 months (29% of cases in 1986-1987 and 43% in 1990-1991). According to ELISA assays, 74-76% of children seroresponded to EZ vaccine administered at age 6-7 months under routine programme conditions., Conclusions: Measles can be controlled in urban areas, although it is difficult to determine how great a contribution vaccination at age 6 months makes over and above the achievement of high coverage.

The response to Edmonston-Zagreb vaccine (titer, 5.4 log10 pfu) was evaluated among children in a study of perinatal transmission of human immunodeficiency virus (HIV) in Kinshasa. Acute postvaccination adverse events were monitored for 49 HIV-infected and 376 non-HIV-infected infants, and measles antibody responses were assessed by ELISA for 34 HIV-infected and 255 non-HIV-infected infants. There was no increase in the incidence of common symptoms 7-10 days after vaccination. HIV-infected infants were more likely to have detectable prevaccination measles antibody, and seroconversion after vaccination was somewhat lower in HIV-infected (76.5%) than non-HIV-infected infants (85.5%). Seroconversion rates did not differ among children with or without rhinitis or fever at vaccination. High-titer Edmonston-Zagreb vaccine given at 6 months of age has the potential to provide earlier protection against measles; however, this vaccine is no longer recommended for routine use, and two doses of standard-titer vaccines remains the preferred option for measles vaccination of HIV-infected infants.

Treatment with high dose vitamin A has recently been recommended for children with measles in communities where vitamin A deficiency is a recognized problem. However, the relationship between vitamin A and measles mortality has not been clearly established. We studied serum vitamin A levels in 283 children less than or equal to 5 years of age admitted to Mama Yemo and Kalembe Lembe Hospitals in Kinshasa, Zaire, between January and March, 1987. Vitamin A levels were determined by high performance liquid chromatography. Vitamin A levels ranged from less than 5 to 63 micrograms/dl (median, 8). The overall case-fatality rate was 26 per cent. On univariate analysis, age less than 24 months, pneumonia on admission, lymphopenia (less than 2000/mm3), and lower vitamin A levels were associated with death during hospitalization. In a multivariate logistic regression model, a vitamin A level less than 5 micrograms/dl was associated with fatal outcome for children younger than 24 months old (relative risk = 2.9, 95 per cent CI 1.3, 6.8), but not for older children. Further studies are needed to determine whether low vitamin A levels predispose children to severe measles and the role of vitamin A supplements in the prevention of measles mortality.