VoICE Immunization Evidence: Growth, Development, and Nutrition
Growth, Development & Nutrition
Undernutrition is a significant risk factor for disease and death in young children, making vaccines especially critical for malnourished children
An analysis of undernutrition and mortality in young children found that among the principal causes of death, 60.7% of deaths as a result of diarrhea, 52.3% of deaths as a result of pneumonia, 44.8% of deaths as a result of measles, and 57.3% of deaths as a result of malaria are attributable to undernutrition.
Malnourished children are at greater risk of death from potentially vaccine-preventable diseases than children with no significant signs of malnourishment.
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.
A study of children under 5 years of age in Dhaka Bangladesh found that severely malnourished children were at a significantly increased risk (nearly 8x) of death from diarrhea than those who were not severely malnourished.
Repeated episodes of diarrhea during infancy and early childhood increases the risk of altered long-term growth and development
The occurence of stunting in children, measured at age 24 months, increased with each diarrheal episode and with each day of diarrhoea prior to their second birthday. The adjusted odds of stunting increased by 13% for every five episodes. In addition, once a child becomes stunted, only 6% of those stunted at 6 months of age recovered by 24 months of age.
In 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.
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.
Data from India’s National Family Health Survey-3 was modeled to determine the contributing factors to height, weight and haemoglobin concentration of over 25,000 children. Results showed that, despite the average child receiving only 1.95 doses of DPT and 2.43 doses of polio vaccinations, and the fact that 45% of children were unimmunized against measles, children’s vaccinations were a statistically significant positive predictor for children’s height, weight and haemoglobin level.
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.
Universal Immunization Programs (UIP) increased the average age-appropriate height and weight of 4 year old children in a study in India. The magnitude of effect suggests that, on average, UIP reduced the height deficit of these children by 22–25% and their weight deficit by 15%.
A study of Kenyan children under 5 years of age found that immunization with polio, BCG, DPT and measles to be protective against stunting in young children; 27% less likely to be stunted than unimmunized children under age 2 years. In addition, 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.
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.
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.
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.”
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.
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.
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.
In a recent review of data from developing countries, researchers found that “episodes of diarrhea may predispose to pneumonia in undernourished children.”