Vaccine coverage and adherence to EPI schedules in eight resource poor settings in the MAL-ED cohort study.

BACKGROUND: Launched in 1974, the Expanded Program on Immunization (EPI) is estimated to prevent two-three million deaths annually from polio, diphtheria, tuberculosis, pertussis, measles, and tetanus. Additional lives could be saved through better understanding what influences adherence to the EPI schedule in specific settings. METHODS: The Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) study followed cohorts in eight sites in South Asia, Africa, and South America and monitored vaccine receipt over the first two years of life for the children enrolled in the study. Vaccination histories were obtained monthly from vaccination cards, local clinic records and/or caregiver reports. Vaccination histories were compared against the prescribed EPI schedules for each country, and coverage rates were examined in relation to the timing of vaccination. The influence of socioeconomic factors on vaccine timing and coverage was also considered. RESULTS: Coverage rates for EPI vaccines varied between sites and by type of vaccine; overall, coverage was highest in the Nepal and Bangladesh sites and lowest in the Tanzania and Brazil sites. Bacillus Calmette-Guérin coverage was high across all sites, 87-100%, whereas measles vaccination rates ranged widely, 73-100%. Significant delays between the scheduled administration age and actual vaccination date were present in all sites, especially for measles vaccine where less than 40% were administered on schedule. A range of socioeconomic factors were significantly associated with vaccination status in study children but these results were largely site-specific. CONCLUSIONS: Our findings highlight the need to improve measles vaccination rates and reduce delayed vaccination to achieve EPI targets related to the establishment of herd immunity and reduction in disease transmission.

Development of the Dzimauli community in Vhembe District, Limpopo province of South Africa, for the MAL-ED cohort study.

The Dzimauli community is located in the Vhembe district in the northern part of Limpopo Province, South Africa. The district is bordered by Botswana and Zimbabwe to the north and Mozambique to the East. The study site population is entirely blacks and 53% female, with a mean household size of 6 persons. Through a consultative process, we engaged and prepared the Dzimauli, a community of low socioeconomic status, to participate in a longitudinal, observational study. In addition to contributing to the objectives of The Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) cohort study, we established a high degree of public trust and understanding of scientific research within the community and its leaders. This has resulted in creating an entirely new site suitable for potential future field-based intervention studies based on an improved understanding of the factors influencing child health in this community.