We combine historical data on the slave trade by ethnic group with individual-level data geolocated at the cluster level from the 2010-2014 Demographic and Health Surveys to examine the relationship between ancestors' exposure to the slave trade and children vaccination status against measles. Exploiting within-location variation, and hence isolating the vertical cultural transmission channel of the slave trade, we find that children from mothers whose ancestors were exposed to the slave trade are less likely to be vaccinated than children living in the same location but with mothers from a slave-free ethnic group. The effect is larger than that of standard determinants of health demand, such as education or revenue, and is not confined to parents health decisions for their children. We find evidence of increased adverse effect of slave trade exposure on contemporaneous demand for vaccination among the descendants whose family has a higher preference for traditional practices and higher incentives to transmit their inherited cultural traits. While we know that there is not a uniform health policy code deemed appropriate for all geographical areas, our results suggest that there is space to integrate ethnic groups' historical-specificity in health policy design and communication.