Immunization is one of the most cost-effective public health interventions to date, saving millions of lives1 and protecting countless children from illness and disability. As a direct result of immunization, polio is on the verge of eradication. Deaths from measles, a major child killer, declined by 71 per cent worldwide and by 80 per cent in sub-Saharan Africa between 2000 and 2011.2 And 31 of 59 priority countries have eliminated maternal and neonatal tetanus.
Immunization has not yet realized its full potential, however. As of end-2013, 21.8 million children under 1 year of age worldwide had not received the three recommended doses of vaccine against diphtheria, tetanus and pertussis (DTP3), and 21.6 million children in the same age group had failed to receive a single dose of measles-containing vaccine. Given an estimated annual cohort of 133.6 million surviving infants, an additional 11.2 million children would need to have been reached during 2013 to attain 90% DTP3 coverage globally.
Many more children could be receiving protection against pneumonia and diarrhoea, two leading causes of child mortality.
Immunization is an affordable means of protecting whole communities from disease and reducing poverty. Immunization coverage for the six major vaccine-preventable diseases – pertussis, childhood tuberculosis, tetanus, polio, measles and diphtheria – has risen significantly since the Expanded Programme on Immunization began in 1974.
An increasing number of countries are now offering pneumococcal conjugate vaccine and rotavirus vaccine in their immunization programmes, thus offering protection against pneumonia and diarrhoea. Use of underutilized vaccines, such as those against yellow fever and Japanese encephalitis, has also been expanded. UNICEF and the World Health Organization (WHO) have broadened their monitoring process accordingly to include coverage of all of these vaccines.
Source: World Health Organization, summary of WHO Position Papers:
ROUTINE IMMUNIZATION COVERAGE
The percentage of children receiving DTP3 is often used as an indicator of how well countries are providing routine immunization services. Global coverage for three doses of DTP-containing vaccine grew from 20 per cent in 1980, to 73 per cent in 2000, to an estimated 84 per cent by the end of 2013.
WHO and UNICEF estimates of national immunization coverage, 2013 revision (completed July 2014).
Despite these advances, many more children could be receiving the benefits of immunization. Of the 21.8 million children worldwide who have not received three doses of DTP-containing vaccine, 75 per cent live in just 15 countries. Absolute numbers of unvaccinated infants are highest in the most populous developing countries, some of which enjoy fairly high rates of immunization coverage. Efforts to raise global immunization levels will require a strong focus on the countries where the highest numbers of unvaccinated children live – while also ensuring that the countries where children are most likely to miss out on immunization are not neglected in the search for greater global impact.
WHO and UNICEF estimates of national immunization coverage, 2013 revision (completed July 2014). Population data for children surviving to 1 year of age obtained from: United Nations, Department of Economic and Social Affairs, Population Division, World Population Prospects: The 2012 revision, United Nations, New York, 2013.
THE GOAL: UNIVERSAL ACCESS
The Global Vaccine Action Plan was endorsed by 194 Member States of the World Health Assembly in May 2012 to achieve the vision of universal access to immunization outlined in the Decade of Vaccines. The action plan is a framework to prevent millions of deaths by 2020 and beyond by:
- Strengthening routine immunization to meet vaccination coverage targets
- Accelerating control of vaccine-preventable diseases with polio eradication as the first milestone
- Introducing new and improved vaccines
- Spurring research and development for the next generation of vaccines and technologies.
Progress on the Global Vaccine Action Plan will be reported annually to the World Health Assembly beginning in 2014.
The Global Vaccine Action Plan builds on the Global Immunization Vision and Strategy 2006─2015, developed by UNICEF, WHO and partners to assist countries in expanding the reach of immunization to every eligible person, including those in age groups beyond infancy. One of its goals is to increase national immunization coverage to at least 90 per cent by 2010 and to sustain such levels through 2015. According to the latest estimates by WHO and UNICEF, 132 of 195 countries or areas attained at least 90 per cent coverage with DTP3 by the end of 2012. Of these 132 countries, 117 countries maintained DTP3 coverage of at least 90 per cent during the three-year period, 2010-2012.
Based on an analysis by Brown et al.3 of mid-term progress, a total of 45 countries made either insufficient or no progress towards the Global Immunization Vision and Strategy goal, as measured by DTP3 coverage. These 45 countries are home to nearly two thirds of the world’s surviving infants not vaccinated with DTP3. Most of these countries are classified as developing or least developed by the World Bank (41 countries); about half are located in Africa (22 countries) and more than half (28 countries) are among the 75 priority countries where more than 95 per cent of all maternal and child deaths occur. Similar patterns were observed for coverage of measles-containing vaccine.
These results suggest that failure to achieve these goals is in part linked to larger systemic shortcomings. They also highlight the importance of a renewed focus on issues of equity in global efforts to raise vaccination coverage levels.
The GAVI Alliance (formerly known as the Global Alliance for Vaccines and Immunization) has developed financial sustainability plans for countries eligible for support. But mobilizing and securing adequate funding will also require stronger political will, better management and greater advocacy.
Increases in routine coverage and improved availability of new vaccines can succeed in reducing child deaths, even in the poorest countries and under difficult circumstances. Strategies to reach every district include re-establishing outreach services, building district-level micro-planning, providing supportive supervision and linking communities with services.
Campaigns such as those for polio eradication and measles mortality reduction have helped strengthen the cold chain and injection safety. Support from the GAVI Alliance for the introduction of new vaccines, including training, demand-creation and cold-chain expansion, are helping boost immunization activities.
Greater attention is also being focused on improving the availability, utilization and retention of home-based vaccination records – either vaccination cards or child health cards. The child immunization card is an inexpensive yet effective instrument for systematically recording the vaccines received by a child. Moreover, the card can enhance health professionals’ ability to make clinical decisions, empower parents/caregivers in the health care of their children, and support public health monitoring. Unfortunately, the child immunization card is often underutilized or misused by parents and health workers and does not always fulfil its intended purpose. Improving the availability, utilization and retention of vaccination cards ultimately will lead to improvements in immunization data quality. An online library, www.immunizationcards.org, has been established to facilitate review and exchange of information on existing vaccination and child health cards, and a website has been developed to monitor the prevalence of vaccination cards through household surveys.
- Levine, O.S., et al., ‘The Future of Immunisation Policy, Implementation, and Financing’, Lancet, vol. 378, 2011, pp. 439─448.
- Updated measles mortality estimates data through 2011 were obtained from Dr. Robert Perry, WHO, Geneva, Switzerland, based on a model reported in: Simons, E., et al., ‘Assessment of the 2010 Global Measles Mortality Reduction Goal: Results from a model of surveillance data’, Lancet , vol. 379, 2012, pp. 2173–2178.
- Brown, D.W., et al., ‘A mid-term assessment of progress towards the immunization coverage goal of the Global Immunization Vision and Strategy (GIVS)’, BMC Public Health, vol. 11, 2011, p. 806.
This immunization summary is a statistical reference containing data through 2010. It was jointly produced by the United Nations Children’s Fund (UNICEF) and the World Health Organization (WHO). It presents detailed statistics on the performance of national and district-level immunization systems in 194 countries and territories.
Country-specific reports of the WHO and UNICEF estimates of national immunization coverage
The graphs and data tables displayed in the country-specific reports show the national coverage levels for each vaccine for the period from 2002 through 2013 (see guide
To access country data please click on country name
Central and Eastern Europe and the Commonwealth of Independent States
East Asia and the Pacific
Eastern and Southern Africa
Latin America and the Caribbean
Middle East and North Africa
West and Central Africa
Since June 2000, WHO and UNICEF have conducted annual reviews of national immunization coverage. Immunization coverage estimates are used for a variety of purposes: to monitor the performance of immunization services at local, national and international levels; to guide polio eradication, measles control and maternal and neonatal tetanus elimination; to identify areas of weak system performance that may require extra resources and focused attention; and as one indicator when deciding whether to introduce a new vaccine. Coverage levels with diphtheria-tetanus-pertussis-containing vaccine (DTP) are considered one indicator of health system performance.
A detailed explanation of the methods behind the WHO and UNICEF estimates of national immunization coverage is provided elsewhere.1,2,3,4 Estimates of immunization coverage are generally based on two sources of empirical data: reports of vaccinations performed by service providers (administrative data5) and household surveys containing items on children's vaccination history (coverage surveys). For estimates based on administrative data, the immunization coverage is derived by dividing the total number of vaccinations given by the number of children in the target population. For most vaccines the target population is the national annual number of births or number of surviving infants (this may vary depending on countries' policies and the specific vaccine). Immunization coverage surveys are frequently used in connection with administrative data. The Expanded Programme on Immunization (EPI) 30-cluster survey, the UNICEF-supported Multiple Indicator Cluster Surveys (MICS) and the Demographic Health Surveys (DHS) supported by the United States Agency for International Development are the principal surveys used as sources of information on immunization coverage.
This review relies on the following data:
- Officially reported data by WHO and UNICEF Member States
- A historical database maintained by UNICEF
- Nationally representative, population-based household survey reports (published and unpublished).
It is important to distinguish whether data accurately reflect immunization system performance or whether they are compromised and thus present a misleading view of immunization coverage. Officially reported data are therefore compared with independent surveys. Based on the data available, the consideration of potential biases and the contributions of local experts, the most likely level of immunization coverage is determined for each country–year–antigen combination. An essential part of this review is consultation and collaboration with national authorities, who are asked to review the draft estimates and provide comments.
- Burton, A., et al., ’A Formal Representation of the WHO and UNICEF Estimates of National Immunization Coverage: A computational logic approach’, PLOS ONE, vol. 7, no. 10:e47806, 2012.
- Kowalski R., A. Burton, ’WUENIC – A Case Study in Rule-based Knowledge Representation and Reasoning’, Lecture Notes in Computer Science, vol. 7258, 2012, pp. 112─125.
- Burton, A., et al., WHO and UNICEF Estimates of National Infant Immunization Coverage: Methods and processes, Bulletin of the World Health Organization, vol. 87, 2009, pp. 535─541.
- Brown DW, Burton AH, Gacic-Dobo M, Karimov RI. An Introduction to the Grade of Confidence Used to Characterize Uncertainty Around the WHO and UNICEF Estimates of National Immunization Coverage. Open Public Hlth J. 2013;6:73-76.
- Administrative data are collected through the WHO/UNICEF Joint Reporting Form on Vaccine-Preventable Diseases, completed annually by countries.
ImmunizationInfo: Expanding access to national immunization coverage estimates
The data above can also be viewed through ImmunizationInfo, an interactive online dissemination tool of national childhood immunization coverage statistics developed in 2010 by UNICEF and WHO in collaboration with Community Systems Foundation. ImmunizationInfo is powered by DevInfo database technology and built using Adobe-Flex technology and allows users to view national immunization coverage estimates in graph, map and table formats based on a user-defined selection of country-year-vaccine combinations. Users can generate comparative graphs and also download the underlying data.