About the Value of Immunization Compendium of Evidence

Value of Immunization Compendium of Evidence (VoICE) is a browsable, searchable database of evidence demonstrating the broad benefit of immunization and the far-reaching impact of vaccine-preventable diseases. The resource is designed to capture the ways in which immunization plays a role in many aspects of health, equity, economics, health system strengthening and other related issues from the individual, country and societal perspective in a way that is easily applicable for those in need of vaccine related health and economic information.

VoICE is a project of the International Vaccine Access Center (IVAC) at Johns Hopkins University, Bloomberg School of Public Health and is made possible with support from the Bill & Melinda Gates Foundation.

Johns Hopkins Bloomberg School of Public Health

The scope of VoICE

Traditionally, the value of immunization has been measured by a vaccine's potential to avert a number of disease episodes or deaths. While VoICE does include, in the Vaccine Resources section, morbidity and mortality data, VoICE's intent is to present the broader continuing and long lasting effects that immunization and vaccine-preventable disease have on the health, economics, societal wellbeing and equity of individuals, communities and nations.

The VoICE Compendium contains more than 450 Key Evidence data summaries from nearly 300 peer-reviewed sources organized under 6 main topic areas and further categorized into 29 subtopics, all illustrating the broad value of immunization and the toll of vaccine-preventable disease.

The 6 main topic areas in the Compendium–Health, Education, Economics, Equity, Health Systems & Integration and Global Issues–contain multiple subtopics, populated with descriptive Key Concepts, each supported by Key Evidence summaries. The Key Evidence summaries are drawn from global peer-reviewed literature and credible scientific and Public Health sources, with an enhanced focus on low- and middle-income countries.  The aim of the Key Evidence statements is to provide synthesized immunization, child health, policy and global health advocacy-focused evidence summaries in easy to articulate messages. VoICE content is designed for child health and immunization advocates and communicators and can be leveraged to strengthen messaging and arguments in support of global advocacy strategies, communications and programs.

The VoICE Featured Issues are created to update and inform the global child health & immunization advocacy community and health-related communications stakeholders about contemporary topics where immunizations intersect with health and economics. These features also serve as an illustration of how evidence-based messages, backed by credible data, can be used to communicate important immunization and health benefit messages to the global community.

Note that VoICE is not intended to represent an exhaustive collection of all available research or evidence on the topic of value of vaccines, nor cover all available or future vaccines to the same extent. Rather, VoICE captures a relevant representation of current available advocacy-focused evidence for each subtopic, rather than serve as a systematic source of evidence for technical decision-making.

Evidence source selection and screening

Most of the sources of information contained in VoICE have been drawn from publications sourced through a recurring monthly systematized search of databases containing scientific and technical peer-reviewed journals. In the absence of peer-reviewed research on a topic, secondary sources may be used which may include expert commentaries or editorials, white papers or reports issued by known researchers and experts. These non peer-reviewed journal sources come only from trusted expert bodies such as the World Health Organization (WHO) or the US Centers for Disease Control (CDC).

Given the exhaustive amount of available information on the value of vaccination and impact of vaccine-preventable disease, we have limited sources contained in the database to those published in English.

About the International Vaccine Access Center at Johns Hopkins University, Bloomberg School of Public Health

The adoption of new vaccines in developing countries has historically been delayed due to a combination of incomplete epidemiological information, outdated policies, and market barriers. Each year that access to vaccines is delayed, millions of children pay with their lives. The International Vaccine Access Center (IVAC) aims to stem this tide by accelerating access to vaccines for children in every corner of the world through data-driven policy making.

IVAC’s work to strengthen the evidence base for vaccine introduction includes undertaking targeted, policy-focused research in areas such as disease burden, cost effectiveness, vaccine policy, demand forecasting, and disease epidemiology.

The time between vaccine development and vaccine introduction in the developing world can be shortened by targeting key decision-makers with irrefutable evidence of the value of vaccines. IVAC leverages its experience from the highly successful Pneumococcal Vaccine Accelerated Development and Introduction Plan (PneumoADIP) and Hib Initiative projects that were based at the Bloomberg School of Public Health. These projects, both supported by Gavi, the Vaccine Alliance, have helped to accelerate the uptake of Hib and pneumococcal conjugate vaccines. Together with rotavirus, also deadly but vaccine-preventable, all three diseases claim the lives of more than 1.5 million children a year. Vaccines for these diseases have been widely used in wealthy countries for years, while children in poor countries have gone without.

IVAC has five teams that work together to support this mission: Epidemiology; Economics & Finance; Operations Research; Policy, Advocacy, & Communications; and Operations.


Learn more about IVAC