Background: One of the agendas of the World Health Organization is to make availability of vaccination to everyone and everywhere by 2030. Nevertheless, about 60% of the world’s children were unvaccinated and not protected from vaccine-preventable diseases. However, there were no enough evidence on the factors contributing to the change in vaccination coverage across residence and concentration of vaccination status across wealth category. Therefore, this study aimed to investigate the factors contributing to the change in children's vaccination inequalities on place of residence and the concentration of vaccination status across the wealth categories among children aged 12-23 months in Ethiopia.

Methods: Maternal and child health services data were extracted from the 2016 Ethiopian Demographic and Health Survey datasets. Consecutively, the multivariate decomposition analysis was done to identify the major factors contributing to the change in percentage of vaccination utilization across place of residence. Similarly, the concentration index and curve were also done to identify the concentration of children vaccination status across wealth categories.

Results: among children aged 12-23 months, the prevalence of fully vaccination status increased from 31.7% in rural to 66.8% in urban residents.  The decomposition analysis indicated that 70.5% of the overall change in vaccination status was due to a difference in respondent’s characteristics. Of the change due to the composition of respondent’s characteristics, wealth index, place of delivery and media exposure were the major contributors for the increase in childhood vaccination. Consecutively, the percentage change in the contribution of child vaccination status among respondents with health facility delivery [β=0.0854; 95%CI: 0.0012, 0.1696], richest wealth status [β= 0.0181; 0.0028, 0.03333], and media exposure [β=0.0740 ;0.0011, 0.1469] were 24.3, 1.9 and 7.9%, respectively.  Among the change due to difference in coefficients, the change in effect of low wealth status across the residences were significantly contributes for the change in child vaccination. On the other hand, the wealth-related inequalities on utilization of child vaccination status were a pro-rich distribution of health services with Concentration Index [CI = 0.1987; P-value < 0.0001].

Conclusion: Change in child vaccination service inequalities was observed across a place of residents and significantly increased from rural to urban. The overall change of the vaccination status of children was due to differences in respondent’s characteristics. Changes in the composition of respondent’s characteristics can be wealth index, place of delivery and media exposure were the major contributors to the increase in childhood vaccination. Similarly, a high concentration of unvaccinated children vaccination was observed among the poorest households. Therefore, health policymakers had better design a compensation mechanism for the costs incurred by the poorest households. Additionally, special emphasis should be given for rural communities through accessing media exposure. Consecutively, community health workers had better a continuous and timely home visit to avoid missed opportunities for child vaccination among home delivery mothers.