VoICE : Search Immunization Evidence
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.
Sustaining immunization activities and preventing vaccine-preventable outbreaks during conflict can be achieved through preemptive preparedness measures and concerted programmatic and financial support from governments and partners.
Key Evidence: During the conflict in Yemen, efforts spearheaded by WHO, with coordination among partners and effective use of resources, especially GAVI, resulted in continued high pentavalent vaccine coverage decreasing only 3% from 2010 to 2015. Yemen also remained polio-free through 2015 and smoothly introduced two new vaccines (MR and IPV).
Key Evidence: During the humanitarian crisis in the Syrian Arab Republic, the constant support from WHO, UNICEF, and local NGOs resulted in immunizations against VPDs reaching over 90% of children.
Integrated community based health intervention programs targeting high risk and underserved populations can lead to significant reductions in socioeconomic inequalities.
Key Evidence: In India, a multi-strategy community intervention, the National Rural Health Mission (NRHM) was successful in reducing disparities between pregnant women who had an institutional delivery in urban and rural areas. Geographic inequities reduced from 22% to 7.6% and socioeconomic disparities declined from 48.2% to 13%. Post the NRHM period, the difference between the number of children with full vaccination i.e., Bacillus Calmette Guerin (BCG) vaccine for tuberculosis, 3 doses of Diphtheria Pertussis and Tetanus vaccine (DTP), 3 doses of Oral Polio Vaccine (OPV), and measles vaccine, in urban and rural areas was observed to be non-significant.
Implementation of community based multi-strategy health intervention programs targeting the at-risk and underserved populations can lead to significant improvements in Maternal & Child Health outcomes.
Key Evidence: Through use of local Maternal Child Health (MCH) incentives, along with the use of locally appointed Health Activists, India’s National Rural Health Mission (NRHM) multiple-strategy community intervention program was able to achieve household level improvements in all of the following indicators for women and children over the 7 year program:
– the proportion of pregnant women having 3 or more ante-natal check-ups (from 43% to 74.5%)
– receiving at least one Tetanus Toxoid injection (from 83.5% to 93.6%)
– institutional deliveries (from 35.7% to 77%)
– post-natal check-ups within 2 weeks of delivery (from 49% to 67.2%) and,
– children who received ORS for diarrhea from (32.3% to 44.8%).
High female under-5 mortality rates, the result of gender bias, highlights the need for more proactive attention to the issue of postnatal sex discrimination.
Key Evidence: An analysis of under-5 mortality rates (U5MR) in India’s 35 states and union territories and 640 districts was conducted in order to estimate excess female mortality. When comparing India’s census data to data from 46 countries without gender bias, researchers found that more than 90% of districts had excess female mortality. The four largest states in northern India accounted for two-thirds of India’s total number. In more than 10% of northern Indian districts, excess U5MR exceeded 30 per 1000 live births, showing that geography is also a key factor in infant and child death among girls. Low economic development, gender inequity, and high fertility were the main predictors of excess female mortality.
Use of vaccines, including strengthening existing immunization programs, provide opportunities for significant reductions in disease burden with resultant economic benefits.
Key Evidence: A study of insurance claims in the U.S. for children under five estimated that, from 2007 to 2011, rotavirus vaccination prevented more than 176,000 hospitalizations, 242,000 emergency room visits and more than 1.1 million outpatient visits due to diarrhea — saving an estimated $924 million in direct health care costs over four years.
Key Evidence: Vaccinating children against rotavirus in Bangladesh would prevent more than 50,000 outpatient visits and 40,000 hospitalizations in children under five each year, and reduce treatment costs by $5.8 million over 2 years — nearly all (96%) from fewer hospitalizations. Since this study didn’t take herd effects into account, the actual impact would likely be greater.
Key Evidence: If China — one of the few remaining countries in the world that haven’t introduced Hib vaccine in their national immunization program — decides to include the vaccine in their program, it could actually be cost saving, that is the vaccination costs would be less than the averted costs of illness from Hib meningitis and pneumonia, if a vaccine price matching UNICEF’s ($2/dose) can be obtained. The vaccination will be cost-effective, but not cost saving, if the program pays the current market priced in China of $10 per dose.
Key Evidence: In a study using actual data on hospitalizations and costs before and after PCV-10 vaccine was introduced in Brazil, an estimated 463,000 hospitalizations from all causes of pneumonia were prevented in persons less than 65 years of age over 5 years following introduction of the vaccine — saving an estimated $147 million in hospitalization costs. Half of the costs averted were due to fewer hospitalizations in children under five, who were targeted for the vaccine, while the remaining half were due to fewer hospitalizations in persons 5-49 years of age, as a result of herd protection.
Key Evidence: In 41 Gavi-eligible countries, it is estimated that without any rotavirus vaccine (RVV) coverage, an estimated 2.2 million Catastrophic Health Costs (CHC) cases and 600,000 Medical Impoverishment (MI) cases would occur due to rotavirus gastroenteritis. Unfortunately these figures would not significantly decrease under the current immunization forecasts because very few countries have introduced the RVV. However, with the introduction of RVV the number of CHC cases would drop to 1.3 million and MI cases to 400,000, representing a 40% reduction.
Key Evidence: Researchers estimate that vaccinating against 10 diseases in the world’s 94 poorest countries between 2011-2020 will avert US$586 billion in costs of illness (including treatment costs, transportation costs, lost caretaker wages and productivity losses due to death and disability). The 73 Gavi-supported countries account for US$544 billion of the treatment costs averted.
The integration of maternal and child health interventions into immunization campaigns can lead to improved rates of immunizations and related healthcare interventions.
Key Evidence: 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.
Vaccines represent a valuable pro-poor intervention that not only improves health but also protects poor households from catastrophic and improverishing health expenditures.
Key Evidence: In 41 Gavi-eligible countries it is estimated that, in the absence of measles vaccination, the occurrence of Medical Impoverishment (MI) or households falling below the poverty line due to medical expenditures to manage measles disease would be 5.3 million. With current coverage rates, 700 thousand households would suffer MI. If Gavi support afforded enhanced coverage, the estimate of households suffering MI would decrease to 500 thousand.
Expanding vaccine coverage would improve household financial well-being by increasing disposable income that could further improve living conditions
Key Evidence: It is estimated that under current vaccine coverage trends in 41 Gavi-eligible countries, enhanced Gavi funding would help to avoid out-of-pocket health expenditures in an amount that surpasses US$4.5 billion attributable to measles, US$168 million attributable to severe pneumococcal disease, and US$200 million attributable to severe rotavirus.
Key Evidence: 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%.
A strong national immunization program can be leveraged during critical health emergencies to aid in outbreak response.
Key Evidence: The detection of H1N1 influenza virus in Mexico in 2009, and subsequently throughout other countries in the Americas, benefited from the laboratory experience with measles and rubella in the region, leading to the rapid detection of and response to what eventually became a novel pandemic virus.