Title : Beyond disease prevention: The impact of rotavirus vaccine rollout on child stunting in Tanzania
Abstract:
Background: Tanzania introduced the rotavirus vaccine in January 2013 to reduce the burden of diarrheal disease, a driver of undernutrition. While the vaccine’s effect on diarrheal morbidity and mortality is well established, limited evidence exists on its broader effect on child growth outcomes – particularly stunting – which affects about 30 percent of Tanzanian children under five.
Methods: Using data from the 2015/16 Tanzania Demographic and Health Survey (TDHS) with a sample of 8949 children, this study applies a reduced-form Regression Discontinuity Design (RDD) exploiting the vaccine eligibility cutoff (children born ≥ November 2012) and Interrupted Time Series Analysis (ITSA) to estimate both immediate and sustained effects of the vaccine rollout on height-for-age z-score (HAZ).
Results: Reduced-form RDD estimates indicate statistically significant improvements in HAZ for vaccine-eligible children. ITSA results show both immediate gains in child growth and a sustained upward trend in HAZ post-vaccine rollout. Robustness checks using placebo cutoffs and falsification outcome suggest that the effects are not driven by confounding factors.
Conclusion: The introduction of the rotavirus vaccine in Tanzania contributed to reductions in stunting by improving long-term growth outcomes. These findings suggest that vaccination provides benefits beyond infection prevention, serving as an investment in human capital. Policy implications include continuing to prioritise zero-dose and under-vaccinated children,integrating vaccination with maternal and nutrition services and strengthening sustainable financing for vaccination.
