The Knowledge Hub

What is the Knowledge Hub?

Explore the VoICE Knowledge Hub—a searchable database featuring the latest peer-reviewed research on immunization benefits, especially in low- and middle-income countries. Browse the Knowledge Hub using a variety of different filters to find vaccine evidence based on country, region, topic, or disease. Click on a tag to find more evidence on a specific area, such as the return on investment of vaccines or impacts of infectious disease outbreaks.


Diseases & Vaccines


WHO Regions


Immunization Terms

Malnourished children are at a greater risk of death from vaccine-preventable diseases

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.

Chisti, M.J., Tebruegge, M., La Vincente, S., et al.. 2009. Pneumonia in severely malnourished children in developing countries – mortality risk, aetiology and validity of WHO clinical signs: a systematic review. Tropical Medicine and International Health. 14(10).

Undernutrition is an underlying cause of child deaths associated with diarrhea, malaria, pneumonia, and measles

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.

Caulfield, L.E., de Onis, M., and Black, R.E.. 2004. Undernutrition as an underlying cause of child deaths associated with diarrhea, pneumonia, malaria and measles. American Journal of Clinical Nutrition. 80(1).

Vaccination linked to higher IQ and language scores

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.

Bloom, D.E., Canning, D., and Weston, M.. 2011. The value of vaccination. Hot Topics in Infection and Immunity in Children VII (Book chapter). vol 697.

Vaccinated children performed better on several cognitive tests

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.)

Bloom, D.E., Canning, D., and Seiguerm E.. 2011. The effect of vaccination on children’s physical and cognitive development in the Philippines. Applied Economics. 44(21).

Diarrhea and respiratory infections are associated with physical stunting in children

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.”

Adair, L.S. and Guilkey, D.K.. 1997. Age-specific determinants of stunting in Filipino children. The Journal of Nutrition. 127.