Immunization Inequality among children of urban poor residents in Nairobi, Kenya

INTRODUCTION:  Health inequality has been recognized as a problem among different populations with inequality concentrating among the poor. Child immunization against vaccine-preventable diseases is crucial in reducing infant and child mortality. The proportion of children fully immunized has increased from 57% in 2003 to 77 in 2008-9. However, there is urban-rural difference with coverage among urban children (80%) somewhat higher than among rural children (76%). Despite high coverage among urban population, the coverage among urban poor remains low. Measurements of health inequalities and the determinants are critical for intervention strategies. The study aims to determine degree of immunization inequality in the informal settlements of Nairobi.

METHODS:  We used data from Nairobi Cross-Sectional Survey 2012 conducted in the informal settlements of Nairobi. The health outcome was child’s fully immunization among children aged 12-23 months. The wealth index based on assets was used as a measure of social economic position. The potential determinants considered included sex of the child and mother’s education, occupation, age at birth of the child, and marital status. The concentration index (CI) was used to quantify the degree of inequality and decomposition approach to assess determinants of inequality in immunization.

RESULTS:  The CI for not fully immunized was -0.15 indicating that immunization practices concentrate among children from relatively least poor families. Results from the decomposition analysis suggest that, for the urban poor population, 51.1% and 13.6% of immunization inequalities are driven majorly by mother’s level of education and mother’s age at birth of the child respectively. 

CONCLUSIONS:  There is immunization inequality among the urban poor residents. Intervention strategies are needed to reduce the inequality which should be supplemented with strategies to improve the education level among women.