Exploring the spatial heterogeneity in different doses of vaccination coverage in India

Despite the universalization of immunization against the six vaccine-preventable diseases (VPDs), the coverage of full immunization among the children under age five has remained a challenge globally. The 2015-16 National Family Health Survey (NFHS) indicated large disparity in the coverage of different vaccination doses (BCG, Polio, DPT and Measles) including full immunization across the districts of India. The spatial distribution of poor performing districts in terms of vaccination and the district level spatial, contextual determinants contributing to the low coverage have been poorly studied. Using the recent household survey (NFHS, 2015-16), this study examined the spatial heterogeneity and the factors associated with low vaccination coverage among the children aged 12-23 months across India.

This study used the data from fourth round of National Family Health Survey conducted in 2015-16. District-level prevalence of each of the vaccination doses including full immunization, were analysed. Moran's I, Univariate and Bivariate LISA, Ordinary least square (OLS) and spatial models were employed to achieve the overall aim of the study.

At the national level, the prevalence of full immunization was 62 percent. Specific vaccination coverage for BCG, three doses of polio, three doses of DPT and measles were 92, 73, 78 and 81 percent, respectively. The value of the bivariate Moran's I statistics confirmed the spatial dependence between specific vaccination and the set of independent variables. District-level prevalence of the specific vaccine and full immunization showed significant spatial clustering across India. The adjusted coefficients from the spatial error model confirmed that district-level proportion of utilization of post-natal care, institutional births, neonatal tetanus protection of the last birth, women's education and coverage of health insurance showed statistically significant association with every doses of vaccination coverage.

The full and specific immunization coverage was considerably low in the geographical hotspots as compared to the national coverage. Maternal and child health care services utilization, financial assistance to the mothers through JSY scheme and mother's education were found to determine full immunization as well as the specific vaccination coverage. Appropriate intervention should be designed to reduce the geographical disparity in the coverage of specific and full immunization across India and thus safeguard child health protecting the children from the vaccine preventable diseases across the geography.