VoICE : Search Immunization Evidence

RESET ALL

Keyword

Topic

Topic

Disease or vaccine

Disease or vaccine

Location

Location

Published year

The VoICE tool is a compendium of the many direct and downstream impacts of vaccine-preventable disease and immunization. The database contains summary explanations of the link between immunization and each impact, as well as sources of evidence for each link. You can browse the VoICE tool by topic, or use the filters to find results based on topic, disease or vaccine, location and published year.

58 Key Ideas, 43 Sources
Key Idea

An analysis of undernutrition and mortality in young children found that among the principal causes of death, 60.7% of deaths occurred as a result of diarrhea, 52.3% of deaths occurred as a result of pneumonia, 44.8% of deaths occurred as a result of measles, and 57.3% of deaths occurred as a result of malaria are attributable to undernutrition.

View Source >

Key Idea

In an effort to reach children with vitamin A deficiency in the African countries of Angola, Chad, Cote d’Ivoire, and Togo, vitamin A supplementation was administered during Polio vaccine campaigns. This led to a minimum coverage of 80% for vitamin A and 84% for polio vaccine in all of the immunization campaigns. During the second year of vitamin A integration into the polio vaccination campaign, coverage exceeded 90% for both vitamin A and polio vaccination in all four countries.

View Source >

Key Idea

In Tanzania, poverty was found to have a negative effect on receiving vaccines on time (at the recommended age). Children in the wealthiest quintile experienced 19% fewer delays for BCG vaccination, 23% fewer delays for the third dose of DTP vaccination, and 31% fewer delays for the first dose of measles-containing vaccine compared to children of the poorest quintile.

View Source >

Key Idea

A study modeling the relationship between disease and poverty in Ethiopia found that among the top 20 causes of death in Ethiopia, diarrhea and lower respiratory infections (LRIs) are the top two drivers of medical impoverishment. It is estimated that in 2013, out-of-pocket direct medical costs for diarrheal disease drove an estimated 164,000 households below the poverty line (representing 47% of all the diarrhea cases), and LRIs led to an estimated 59,000 cases of poverty (17% of LRI cases). Of the top 10 health-associated drivers of poverty, four are at least partially vaccine-preventable (1. Diarrhea, 2. LRI, 4. TB. 10. Pertussis).

View Source >

Key Idea

Children in Tanzania living 5 km or greater distance from the nearest healthcare facility were less likely to be immunized than children living less than 5 km from facilities. Compared to children living close a health facility, children far from a health facility had almost three times the risk of missing out on BCG, 84% higher risk of missing the third dose of DTP, and 48% higher risk of missing the first dose of measles-containing vaccine. Of children who did receive BCG, those living more than 5 km from facilities were 26% more likely to received BCG vaccine late than children close to the facility.

View Source >

Key Idea

In urban residents in the Democratic Republic of Congo, chronically malnourished children were less likely to have received two doses of measles-containing vaccine compared to healthy children (OR=0.4).

View Source >

Key Idea

Across many South Asian and sub-Saharan African countries, children of mothers who received no formal education were nearly 3 times as likely to die before reaching age 5 as those born to mothers with some secondary education.

View Source >

Key Idea

Children living in the Yida refugee camp in South Sudan in 2013 were found to have an elevated rate of pneumonia infections likely due to malnutrition, overcrowding, and inadequate shelter. Using these data, the CDC estimated that the use of Hib and pneumococcal vaccines in children under 2 years of age in the camp would be cost-effective under all dosing scenarios evaluated. Medecines Sans Frontiers (MSF) provided medical services to this refugee camp and found delivery of these vaccines to be feasible and effective in this setting.

View Source >

Key Idea

An analysis of the impact of rotavirus vaccine in 25 Gavi countries found that the rates of vaccination in all countries were highest, and risk mortality lowest, in the top two wealth quintiles’ coverage. Countries differed in the relative inequities in these two underlying variables. Cost per DALYs averted is substantially greater in the higher quintiles. In all countries, the greatest potential vaccine benefit was in the poorest quintiles; however, reduced vaccination coverage lowered the projected vaccine benefit.

View Source >

A study looking at the impact of pneumococcal vaccine introduction and scaling up pneumonia treatment in Ethiopia found that 30-40% of all deaths averted by these interventions would be expected to occur in the poorest wealth quintile. The greatest resulting financial risk protection would also be concentrated among the bottom income quintile.

View Source >

Key Idea

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.

View Source >

Key Idea

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.

View Source >

Key Idea

A study of 14 geographically diverse countries with a DPT vaccination rate below 70% evaluated missed vaccination opportunities. Researchers found that children – and their mothers – who were fully immunized were more likely to have received other health interventions. In Cote d’Ivoire, children of mothers who had four or more antenatal care (ANC) visits were 54% more likely to be fully immunized than children of mothers who had no ANC visits. Large differences in full immunization coverage were also found in children who received Vitamin A vs. children who didn’t (greatest difference of 41% was noted in the DRC) and in mothers who had access to a skilled birth attendance (36 % difference in Nigeria) and postnatal care (31% difference in Ethiopia), as compared to mothers without access to these services.

View Source >

Key Idea

A study of over 80,000 children in Kenya designed to understand the role of inadequate health systems on childhood survival beyond 59 months of age showed that a higher per capita density of heath facilities resulted in a 25% reduction in the risk of death. However, user fees for sick-child visits increased the risk of death by 30%.

View Source >

Key Idea

The 2008 Nigerian Demographic Health Survey data suggest that children in communities with high unemployment were 1/3 as likely to be fully immunized than children in communities with a medium level of unemployment.

View Source >

Key Idea

A study looking at the relationship between gender roles and full immunization coverage of children in Nigeria found that children of mothers who did not have decision-making autonomy were half as likely to be fully immunized than mothers with autonomy. To further assess the roles of gender and relationship power, children were nearly twice as likely to be fully vaccinated in households where only the mother contributed to household earnings compared to children whose parents contributed equally.

View Source >

Key Idea

The evidence on cholera disease dynamics suggests that significant herd protection can result from a relatively small number of immunizations, particularly in endemic areas where there is some natural immunity among the population.

View Source >

Key Idea

A multi-site study of cholera vaccination programs found that the vaccine was cost-effective in school- and community-based vaccination programs for children in India, Mozambique, and Indonesia.

View Source >

Assuming 90% coverage, a program in The Gambia using a 9-valent PCV (PCV9) would prevent approximately 630 hospitalizations, 40 deaths, and 1,000 DALYs over the first 5 years of life of a birth cohort. The estimated cost would be US$670 per DALY averted in The Gambia.

View Source >

Key Idea

A study looking at the impact of pneumococcal vaccine introduction and scaling up pneumonia treatment in Ethiopia found that 30-40% of all deaths averted by these interventions would be expected to occur in the poorest wealth quintile. The greatest resulting financial risk protection would also be concentrated among the bottom income quintile.

View Source >

Key Idea

Among families participating in a study in Western Cape, South Africa, 35% of mothers who were previously employed stopped working to care for children who had survived tuberculosis meningitis with permanent disabilities. 19% of families reported experiencing financial loss as a result of caring for these disabled children.

View Source >

Key Idea

In a study in The Gambia – a setting where healthcare is free of charge to patients – pneumococcal disease nonetheless placed a heavy financial burden on families seeking treatment before arrival at the hospital, with families paying for transportation costs, drugs, diagnostic tests and even burial in the case of death. 50-80% of the cost of treating an episode of pneumococcal disease was born by the health system, which still left families to cover a cost up to 10 times their average daily household budget. In addition the estimated treatment cost for inpatient pneumonia of US$109 is nearly 4 times the annual per capita expenditure for health in The Gambia.

View Source >

In Malawi, in 17% of cases where children were admitted to the hospital, and in 9% of cases where children were treated as outpatients for diarrhea, household costs associated with treating that episode, exceeded monthly income in a significant number of cases. The costs were significant enough to push families from each income level below the national poverty line for the month in which the illness occurred.

View Source >

Key Idea

For every 6 children vaccinated against measles in a poor, largely rural community in South Africa, one additional grade of schooling was achieved.

View Source >

Key Idea

Models based on demographic data from Ghana suggest that immunization would eliminate the childhood mortality risk associated with living in poverty and greatly diminish the increased risk of mortality borne by children whose parents have low levels of education.

View Source >

Key Idea

Among families participating in a study in Western Cape, South Africa, 35% of mothers who were previously employed stopped working to care for children who had survived tuberculosis meningitis resulting in permanent disabilities. 19% of families reported experiencing financial loss as a result of caring for these disabled children.

View Source >

Key Idea

In The Gambia, 58% of children who survived a bout of pneumococcal meningitis “had clinical sequelae; half of them had major disability preventing normal adaptation to social life” (mental retardation, hearing loss, motor abnormalities, seizures).

View Source >

In a systematic literature review of studies in Africa, it was found that one quarter of children who survived pneumococcal or Hib meningitis had neuropsychological deficits.

View Source >

Key Idea

Among children participating in a study in Western Cape, South Africa who were well enough to attend school after surviving tuberculous meningitis, more than half (53%) had failed a school grade at least once.

View Source >

Key Idea

For every 6 children vaccinated against measles in a poor, largely rural community in South Africa, one additional grade of schooling was achieved.

View Source >

Key Idea

Nigerian Demographic Health Survey data suggests that community literacy influences immunization status. Children in communities with low levels of illiteracy were 82% less likely to be fully immunized than children in communities with medium levels of illiteracy.

View Source >

A study conducted in Eastern Uganda found that Ugandan children whose mothers had some secondary schooling were 50% more likely to have received scheduled vaccinations by 6 months of age than children whose mothers had attended school only through primary level. This effect became more pronounced with delivery of the later doses of each vaccine (OPV2, 3 & DPT-HB-Hib 2,3).

View Source >

Key Idea

In Rwanda, HPV vaccine introduction through a new school-based delivery program provided the opportunity to offer additional health services to all school-children (girls and boys), including health promotion sessions, de-worming and opportunities for voluntary, free circumcision.

View Source >

Key Idea

In a systematic review of qualitative research from low- and middle-income countries, women’s low social status was shown to be a barrier to their children accessing vaccinations. Specific barriers included access to education, income, resource allocation, and autonomous decision-making related to time. The authors suggest that expanding the responsibility for children’s health to both parents (mothers and fathers) may be one important element in removing persistent barriers to immunization often faced by mothers.

View Source >

The level of women’s community-level autonomy is associated with an increased number of children immunized above and beyond that which is seen with individual-level women’s autonomy. These results indicate that empowering women within households not only improves the individual mother’s children’s health, but also serves to improve the lives of other children within the community.

View Source >

A systematic review of studies from countries in Africa and Southeast Asia investigated the relationship between a woman’s “agency” (defined as the woman’s ability to state her goals and to act upon them with motivation and purpose) and childhood immunizations in lower-income settings. The review found a general pattern among studies in which higher agency among mothers was associated with higher odds of childhood immunizations. Empowering women in these settings shows promise as a means to improve child health.

View Source >

Key Idea

In a study in The Gambia – a setting where healthcare is free of charge to patients – pneumococcal disease nonetheless placed a heavy financial burden on families seeking treatment before arrival at the hospital, with families paying for transportation costs, drugs, diagnostic tests and even burial in the case of death. 50-80% of the cost of treating an episode of pneumococcal disease was born by the health system, which still left families to cover a cost up to 10 times their average daily household budget. In addition the estimated treatment cost for inpatient pneumonia of US$109 is nearly 4 times the annual per capita expenditure for health in The Gambia.

View Source >

Key Idea

An ecological study designed to investigate the association between child mortality rates and gender inequality using the United Nations Development Programme’s Gender Inequality Index (GII), showed that low- and middle-income countries have significantly higher gender inequality and under-5 mortality rates than high-income countries. Greater gender inequality was significantly correlated with lower immunization coverage and higher neonatal, infant, and under-5 mortality.

View Source >

Key Idea

Among both HIV positive and HIV negative parents in a study in Kenya, 99% of pneumococcal strains found and tested were resistant to one or more antibiotics. HIV positive parents carried 16% more strains that were resistant to penicillin than those carried by HIV negative parents.

View Source >

In a study of national surveillance records in South Africa, HIV positive people over 5 years of age were found to have a 43-fold risk of invasive pneumococcal disease compared to HIV negative person. This risk was highest among children age 5-19 who were found have a more than 120-fold risk of invasive pneumococcal disease compared to HIV negative uninfected children of the same age. 90% of South Africa’s invasive pneumococcal disease cases during the 5 year period occurred in the 18% of the population who are HIV positive.

View Source >

Key Idea

Models based on demographic data from Ghana suggest that immunization would eliminate the childhood mortality risk associated with living in poverty and greatly diminish the increased risk of mortality borne by children whose parents have low levels of education.

View Source >

Key Idea

A review of evidence for the use of pneumococcal conjugate vaccine in South Africa showed that children who are HIV positive are at significantly increased risk of pneumococcal disease, and so will benefit the most from vaccination, despite decreased vaccine efficacy in this group compared to healthy children.

View Source >

A large randomized controlled trial of a pneumococcal conjugate vaccine in South Africa found that use of the vaccine prevented 10 times as many cases of pneumococcal pneumonia in HIV positive children than in HIV negative children.

View Source >

Key Idea

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.

View Source >

An analysis of undernutrition and mortality in young children found that among the principal causes of death, 60.7% of deaths occurred as a result of diarrhea, 52.3% of deaths occurred as a result of pneumonia, 44.8% of deaths occurred as a result of measles, and 57.3% of deaths occurred as a result of malaria are attributable to undernutrition.

View Source >

Key Idea

A study looking at the impact of pneumococcal vaccine introduction and scaling up pneumonia treatment in Ethiopia found that 30-40% of all deaths averted by these interventions would be expected to occur in the poorest wealth quintile. Scaling up PCV13 to levels achieved with DTP3 in Ethiopia would be expected to avert nearly 3000 child deaths and 60,000 episodes of pneumococcal pneumonia annually, not including any potential herd benefit. A publicly financed program to scale up pneumococcal vaccines would cost about US$40 per year of healthy life gained.

View Source >

Key Idea

A package of 5 vaccines was delivered, and it was found that children from poorer households benefited more in terms of health outcomes from immunization than did those from relatively wealthier households. Results suggest that most of the risk of dying before age five can be eliminated with full immunization in the severely health-deprived setting.

View Source >

Key Idea

Rates of vaccination in all studied countries were highest and risk mortality lowest in the top two wealth quintile’s coverage. Countries differed in the relative inequities in these two underlying variables. Cost per DALYs averted is substantially greater in the higher quintiles. In all countries, the greatest potential vaccine benefit was in the poorest quintiles; however, reduced vaccination coverage lowered the projected vaccine benefit.

View Source >

Key Idea

In a systematic review of qualitative research from low- and middle-income countries, women’s low social status was shown to be a barrier to their children accessing vaccinations. Specific barriers included access to education, income, resource allocation, and autonomous decision-making related to time. The authors suggest that expanding the responsibility for children’s health to both parents (mothers and fathers) may be one important element in removing persistent barriers to immunization often faced by mothers.

View Source >

In Tanzania, poverty was found to have a negative effect on receiving vaccines on time (at the recommended age). Children in the wealthiest quintile experienced 19% fewer delays for BCG vaccination, 23% fewer delays for the third dose of DTP vaccination, and 31% fewer delays for the first dose of measles-containing vaccine compared to children of the poorest quintile.

View Source >

Key Idea

A package of 5 vaccines was delivered, and it was found that children from poorer households benefited more in terms of health outcomes from immunization than did those from relatively wealthier households. Results suggest that most of the risk of dying before age five can be eliminated with full immunization in the severely health-deprived setting.

View Source >

Key Idea

This study from South Africa demonstrates significant declines in invasive pneumococcal disease cases caused by bacteria that are resistant to one or more antibiotics. In fact, the rate of infections resistant to two different antibiotics declined nearly twice as much as infections that could be treated with antibiotics.

View Source >

Key Idea

Among both HIV positive and HIV negative parents in a study in Kenya, 99% of pneumococcal strains found and tested were resistant to one or more antibiotics. HIV positive parents carried 16% more strains that were resistant to penicillin than those carried by HIV negative parents.

View Source >

Key Idea

Children living in the Yida refugee camp in South Sudan in 2013 were found to have an elevated rate of pneumonia infections likely due to malnutrition, overcrowding, and inadequate shelter. Using these data, the CDC estimated that the use of Hib and pneumococcal vaccines in children under 2 years of age in the camp would be cost-effective under all dosing scenarios evaluated. Medecines Sans Frontiers (MSF) provided medical services to this refugee camp and found delivery of these vaccines to be feasible and effective in this setting.

View Source >

Key Idea

Researchers investigating the causes of a measles outbreak in Burkina Faso that occurred despite a recent mass vaccination campaign found that migration to and from Cote d’Ivoire was a major risk factor for children. Unvaccinated children who developed measles were 8.5x more likely to have recently traveled to Cote d’Ivoire than unvaccinated children who had not traveled across the border. Children returning to Burkina Faso after a period of time in Cote d’Ivoire were less likely to have been vaccinated due to low routine coverage of measles vaccines in Cote d’Ivoire. Conversely, unvaccinated children from Burkina Faso who traveled to Cote d’Ivoire and returned were more likely to be exposed to measles and thus had a higher rate of disease than children who never visited Cote d’Ivoire.

View Source >

Key Idea

A study from South Africa shows that reduced birth rates (fertility) lead to: 1) “decreasing ratio of economically dependent people” 2) “increasing labour force per capita” 3) “[increased] savings 4) “savings can be invested in the physical and human capital needed for economic growth” 5)”As average family size decreases, parents are likely to invest more in the education and health of each child, leading to improved productivity in adulthood.”

View Source >

Key Idea

A study of Kenyan children under 5 years of age found immunization with polio, BCG, DPT, and measles to be protective against stunting in young children; they were 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.

View Source >

Key Idea

In Rwanda, the number of hospital admissions for diarrhea and rotavirus fell substantially after rotavirus vaccine (RVV) introduction, including among older children age-ineligible for vaccination. This suggests indirect protection through reduced transmission of rotavirus. Two years after RVV introduction, the country had nearly 400 fewer hospital admissions for diarrhea among young children.

View Source >

Key Idea

Multiple studies show that

  1. Diarrhea and pneumonia impair children’s growth and that underlying malnutrition is a major risk factor for these conditions.
  2. “Episodes of diarrhea may predispose to pneumonia in undernourished children” and
  3. 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.

View Source >

Key Idea

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.

View Source >

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.

View Source >

Key Idea

In a recent review of data from developing countries, researchers found that episodes of diarrhea may predispose undernourished children to pneumonia.

View Source >

Key Idea

Assuming 90% coverage, a program in The Gambia using a 9-valent PCV (PCV9) would prevent approximately 630 hospitalizations, 40 deaths, and 1000 DALYs over the first 5 years of life of a birth cohort. The estimated cost would be $670 per DALY averted in The Gambia.

View Source >

Key Idea

In Gambia, 58% of children who survived a bout of pneumococcal meningitis “had clinical sequelae; half of them had major disability preventing normal adaptation to social life” (mental retardation, hearing loss, motor abnormalities, seizures).

View Source >

In a systematic literature review of studies in Africa, the authors conclude: “Bacterial meningitis in Africa is associated with high mortality and risk of neuropsychological sequelae. Pneumococcal and Hib meningitis kill approximately one third of affected children and cause clinically evident sequelae in a quarter of survivors prior to hospital discharge. The three leading causes of bacterial meningitis are vaccine preventable, and routine use of conjugate vaccines could provide substantial health and economic benefits through the prevention of childhood meningitis cases, deaths, and disability.”

View Source >

Key Idea

The Government of Nigeria used the Incident Management System (IMS) to establish a national Emergency Operations Center (EOC) as part of a new national emergency plan for the global polio eradication initiative. The use of IMS through the EOC changed the operational tempo, accountability measures, and programmatic success of the polio program. This existing infrastructure was in place and leveraged to contain the outbreak of Ebola.

View Source >

Key Idea

In Rwanda, HPV vaccine introduction through a new school-based delivery program provided the opportunity to offer additional health services to all school-children (girls and boys), including health promotion sessions, de-worming and opportunities for voluntary, free circumcision.

View Source >

Key Idea

The Government of Nigeria used the Incident Management System (IMS) to establish a national Emergency Operations Center (EOC) as part of a new national emergency plan for the global polio eradication initiative. The use of IMS through the EOC changed the operational tempo, accountability measures, and programmatic success of the polio program. This existing infrastructure was in place and leveraged to contain the outbreak of Ebola.

View Source >

Key Idea

In Rwanda, HPV vaccine introduction through a new school-based delivery program provided the opportunity to offer additional health services to all school-children (girls and boys), including health promotion sessions, de-worming and opportunities for voluntary, free circumcision.

View Source >

Key Idea

Two years after rotavirus vaccine introduction in Rwanda, the country saw nearly 400 fewer hospital admissions for diarrhea among young children at 24 district hospitals.

View Source >

Key Idea

Among the principal causes of death in young children, 60.7% of deaths occurred as a result of diarrhea, 52.3% of deaths occurred as a result of pneumonia, 44.8% of deaths occurred as a result of measles, and 57.3% of deaths occurred as a result of malaria are attributable to under nutrition.

View Source >