Effect of vaccination on children's learning achievements: findings from the India Human Development Survey.

Background: Beyond the prevention of illness and death, vaccination may provide additional benefits such as improved educational outcomes. However, there is currently little evidence on this question. Our objective was to estimate the effect of childhood vaccination on learning achievements among primary school children in India.
Methods: We used cohort data from the India Human Development Survey. Vaccination status and confounders were measured among children who were at least 12 months old at baseline in 2004-2005. In 2011-2012, the same children completed basic reading, writing and math tests. We estimated the effect of full vaccination during childhood on learning achievements using inverse probability of treatment-weighted logistic regression models and results reported on the risk difference scale. The propensity score included 33 potential community-, household-, mother- and child-level confounders as well as state fixed effects.
Results: Among the 4877 children included in our analysis, 54% were fully vaccinated at baseline, and 54% could read by the age of 8-11 years. The estimated effect of full vaccination on learning achievements ranged from 4 to 6 percentage points, representing relative increases ranging from 6% to 12%. Bias analysis suggested that our observed effects could be explained by unmeasured confounding, but only in the case of strong associations with the treatment and outcome.
Conclusion: These results support the hypothesis that vaccination has lasting effects on children's learning achievements. Further work is needed to confirm findings and elucidate the potential mechanisms linking vaccines to educational outcomes.
Competing Interests: Competing interests: None declared.
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