<p>Despite economic progress in BRICS countries, infant mortality remains a major public health concern. Existing studies have examined some of its determinants but have rarely considered the heterogeneous associations between DPT and measles immunizations and key macroeconomic and demographic factors in a distributional panel framework. Guided by Grossman’s health capital framework, this study investigates the associations between DPT and measles immunizations, health expenditure, GDP per capita, urbanization, and infant mortality across BRICS countries from 2000 to 2025. The analysis applies panel quantile regression, supported by robustness checks using PCSEs and DKSE, as well as the Dumitrescu-Hurlin panel causality test. The results show that DPT and measles immunizations, as well as health expenditure, exhibit mixed associations across quantiles. GDP per capita is negatively associated with infant mortality across much of the distribution, while urbanization shows a less uniform but generally negative association. The Dumitrescu-Hurlin panel causality results indicate significant predictive linkages among several variables, though these should not be read as definitive causal effects. Taken together, the findings suggest that BRICS policymakers should give particular attention to strengthening routine immunization systems, improving the allocation and effectiveness of health spending, and aligning broader economic and urban development strategies with child survival objectives.</p>