Findings of a systematic review evaluating the relationship between pneumonia and malnourishment found that severely malnourished children in developing countries had 2.5 to 15 times the risk of death. For children with moderate malnutrition, the risk of death ranged from 1.2 to 36.
An analysis of the association between undernutrition and mortality in young children revealed that in 60% of deaths due to diarrhea, 52% of deaths due to pneumonia, 45% of deaths due to measles and 57% of deaths attributable to malaria, undernutrition was a contributing factor.
Vaccination of children in the Philippines against 6 diseases was found to significantly increase IQ and language scores (compared to children receiving no vaccinations) and was estimated to have a 21% rate of return.
In a study of immunization in the Philippines, children vaccinated against 6 diseases performed significantly better on verbal reasoning, math, and language tests than those who were unvaccinated. (note: Researchers did not find an association with physical growth.)
A large longitudinal study in the Philippines found that children suffering bouts of diarrhea and respiratory infections were at a significantly increased risk of physical stunting which is associated with “poor functional outcomes such as impaired cognitive development.”