Progress in reaching unvaccinated (zero-dose) children in India, 1992–2016: a multilevel, geospatial analysis of repeated cross-sectional surveys

Reaching zero-dose children (infants who receive no routine vaccinations) is a global strategic priority. Using four rounds of nationally representative survey data, we studied the situation of zero-dose children in India over a 24-year timeframe from 1992 to 2016. Our aim was to trace aggregate trends and to clarify the contribution of large-scale social, economic, and geographical inequalities to child zero-dose status. We found that, over the 24-year analysis timeframe, the proportion of zero-dose children in India declined by 23·3% in absolute terms, with more rapid reductions among the worst off. Yet, despite tremendous progress, we found that child zero-dose status was shaped by large-scale social inequalities and remained a consistent marker of generalised vulnerability. These results yield insights into the complex causes of social disadvantage facing zero-dose children and informed our intervention approach. To disrupt the cycle of intergenerational inequities, our approach strives both to address under vaccination and to mitigate the underlying determinants that contribute to it.