VoICE Immunization Evidence: Growth, Development, and Nutrition
Growth, Development & Nutrition
Repeated episodes of diarrhea during infancy and early childhood increases the risk of altered long-term growth and development
Key Evidence: A pooled analysis of nine studies assessing the effects of diarrhea on stunting prior to the age of 24 months showed that the odds of stunting were significantly increased with each diarrheal episode. Each day of diarrhea prior to attaining 24 months of age also contributed to the risk of stunting. For each five episodes of diarrhea, the odds of stunting increased by 13%. In addition, once a child becomes stunted, only 6% of those stunted at 6 months of age recovered by 24 months of age.
Key Evidence: A review of gut infections and effects on physical growth and development found that for children living in impoverished areas of the world, episodes of diarrhea during the first two years of life not only negatively affected their physical growth, but could result in a 10 points lower IQ than average by age 7.
Key Evidence: An analysis conducted in areas of Ethiopia with high proportions of refugees found that high measles vaccination coverage was linked to lower rates of acute malnutrition (wasting) in children under five. For each percentage point increase in measles vaccination coverage, there was a 0.65% decrease in the rate of acute malnutrition in these areas.
From the VoICE Editors: The analysis was conducted on data from more than 150 nutrition surveys.
Undernutrition is a significant risk factor for disease and death in young children, making vaccination especially critical for this population.
Key Evidence: 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.
Key Evidence: The presence of malnourishment correlates with the severity of cholera illness. Additional factors include the number of V. cholerae bacteria ingested, lack of immunity from prior exposure or vaccination, pregnancy, lack of breast-feeding, immunocompromised state, reduced ability to produce gastric acid, and having blood group O.
Children with malnutrition are at greater risk of death from vaccine-preventable diseases than are children with no significant signs of malnourishment.
Key Evidence: 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.
Key Evidence: A study of children under 5 years of age in Dhaka, Bangladesh found that severely malnourished children were nearly 8 times more likely to suffer death from diarrhea than those who were not severely malnourished.
Key Evidence: Respiratory infections during pregnancy may exert indirect effects on the developing fetus through placental function and maternal immune responses. This in turn may lead to pre term births and reduced growth of the fetus. However, a review of recent studies, researchers show that administration of influenza vaccine during pregnancy adds 200 grams to newborn weight and that PCV7 vaccine given to infants translates into an additional 500 grams of growth in the first 6 months of life. In addition, maternal influenza vaccine led to a 15% reduction in low birth-weight. This indicates that immunization can improve intrauterine growth.
Key Evidence: In a study of families living on 24 plantations in Indonesia, the community immunization rate was found to be protective against thinness for age in children. In other words, children in communities with higher overall levels of immunization had better nutritional status.
Key Evidence: Modeling of data from India’s National Family Health Survey-3 indicated that vaccinations against DPT, polio and measles were significant positive predictors of a child’s height, weight and hemoglobin concentration. This was ascertained post modeling of data obtained from over 25,000 children.
Key Evidence: This study, conducted in the United States, demonstrates an association between immunization with the inactivated influenza vaccine during pregnancy and reduced likelihood of prematurity during local, regional, and widespread influenza activity periods. Moreover, during the period of widespread influenza activity there was an association between maternal receipt of influenza vaccine and reduced likelihood of small for gestational age (SGA) birth.
Key Evidence: Children enrolled in Universal Immunization Programs observe improvements in terms of age-appropriate height and weight as per results of a study focused on 4 year old children in India. On an average height and weight deficits were reduced by 22-25% and 15% respectively.
Key Evidence: A study in Kenya revealed that immunization with polio, BCG, DPT and measles had protective effects with respect to stunting in children under 5 years of age. In children under the age of 2 years, immunized children were 27% less likely to experience stunting when compared to unimmunized children. Additionally, children who suffered from cough or diarrhea in the 2 weeks prior to the study showed an 80-90% higher probability of being underweight or experiencing wasting.
The interactions of childhood diarrhea, pneumonia and malnutrition contribute to a vicious cycle of poor health and delayed growth and development. Immunization can help to improve this cycle.
Key Evidence: Multiple studies show that
- Diarrhea and pneumonia impair children’s growth and that underlying malnutrition is a major risk factor for these conditions.
- “Episodes of diarrhea may predispose to pneumonia in undernourished children” and
- Immunization against influenza (in mothers) and Streptococcus pneumoniae may improve infant growth. In addition, new studies from Bangladesh, Colombia, Ghana, and Israel further support the paradigm that malnutrition is a key risk factor for diarrhea and pneumonia.
Vaccine preventable diseases are linked to poor growth and can further impact an already weakened immune system.
Key Evidence: 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.”
Key Evidence: A prospective case-control study conducted in several developing countries found that children with moderate-to-severe diarrhea grew significantly less in length in the two months following their episode compared to age- and gender-matched controls.
Key Evidence: In a study conducted in Southern India, pneumococcal carriage at age 2 months was associated with a 3-fold risk of stunting and decreased weight, length, and length-for-age by 6 months of age. Pneumococcal carriage at 4 months of age did not affect growth.
Key Evidence: A study of Kenyan children under 5 years of age found that children with diarrhea and cough in the 2 weeks prior to the survey were 80-90% more likely to be underweight or to suffer from wasting.
Vaccine-preventable diseases such as pneumonia and diarrhea can predispose children to further infections.
Key Evidence: In a recent review of data from developing countries, researchers found that episodes of diarrhea may predispose undernourished children to pneumonia.