Global Routine Vaccination Coverage, 2010

Global Routine Vaccination Coverage, 2010Weekly
November 11, 2011 / 60(44);1520-1522

The Expanded Program on Immunization was established by the World Health Organization (WHO) in 1974 to ensure universal access to routinely recommended childhood vaccines. Six vaccine-preventable diseases initially were targeted: tuberculosis, poliomyelitis, diphtheria, tetanus, pertussis, and measles. In 1974, fewer than 5% of the world's infants were fully immunized (1); by 2005, global coverage with the third dose of diphtheria-tetanus-pertussis (DTP) vaccine (DTP3) was 79%, but many children, especially those living in poorer countries, still were not being reached. That year, WHO and the United Nations Children's Fund (UNICEF) developed the Global Immunization Vision and Strategy (GIVS), with the aim of decreasing vaccine-preventable disease--related morbidity and mortality by improving national immunization programs (2). One goal of GIVS was for all countries to achieve 90% national DTP3 coverage by 2010. This report summarizes the status of vaccination coverage globally and regionally in 2010 and progress toward meeting the GIVS goal. In 2010, 130 (67%) countries had achieved 90% DTP3 coverage, and an estimated 85% of infants worldwide had received at least 3 doses of DTP vaccine. However, 19.3 million children were not fully vaccinated and remained at risk for diphtheria, tetanus, and pertussis and other vaccine-preventable causes of morbidity and mortality; approximately 50% of these children live in India, Nigeria, and the Democratic Republic of Congo. Despite the overall improvement in vaccination coverage during the past 37 years, routine vaccination programs need to be strengthened globally, especially in countries with the greatest numbers of unvaccinated children.

Coverage with routinely administered vaccines is used as a measure of program performance and population immunity, and is assessed as the percentage of children who have received the appropriate number of doses of a recommended vaccine during the first year of life. Administrative coverage estimates, derived by dividing the number of vaccine doses reported administered to the target population by the estimated number of persons in the target population, are reported annually to WHO and UNICEF by WHO member states, and can be supplemented by special coverage surveys and other published and unpublished data (3). WHO and UNICEF derive national estimates of vaccination coverage through a country-by-country review of the best available data (4). These estimates are published annually on the WHO website* and are updated after publication if additional data become available. DTP3 coverage by age 12 months serves as the primary indicator of immunization program performance; however, coverage with other recommended vaccines, including the third dose of polio vaccine and the first dose of measles-containing vaccine (MCV1), are additional indicators of program strength.

In 2010, estimated global DTP3 coverage among children aged <12 months was 85%, representing 109.4 million immunized children (Table), slightly higher than the estimated coverage in 2009 (82%) (3). DTP3 coverage in 2010 ranged from 77% in the African and South-East Asian WHO regions to 96% in the Western Pacific and European regions. Of 193 WHO member states, 130 (67%) met the 2010 GIVS target of ≥90% national DTP3 coverage. Fifty-nine (30%) member states reported achieving a second GIVS target of ≥80% DTP3 coverage in every district. Estimated DTP3 coverage was 80%--89% in 30 (16%) countries, 70%--79% in 15 (8%) countries, and <70% in 18 (9%) countries. Of the 19.3 million children who had not received DTP3 during the first year of life, three countries accounted for approximately half of undervaccinated children: India (37%), Nigeria (9%), and the Democratic Republic of Congo (5%) (Figure). Ten countries accounted for 69% of undervaccinated children.

Estimated global coverage was 90% for Bacille Calmette-Guérin vaccine,† 86% for the third dose of polio vaccine, and 85% for MCV1 (Table). Coverage varied by WHO region, and was highest in the European (96%), Western Pacific (96%), and American (93%) regions. By the end of 2010, a total of 179 countries (including parts of India and Sudan) had introduced hepatitis B (HepB) vaccine in routine vaccination programs; 93 (52%) of these countries had a recommendation to administer the first dose of vaccine within 24 hours of birth to prevent perinatal hepatitis B virus transmission. Coverage with 3 doses of HepB vaccine (HepB3) was 75% globally and ranged from 52% to 91% by region (Table). Coverage with Haemophilus influenzae type b (Hib) vaccine, which had been introduced in 169 countries (including parts of Sudan, Philippines, and Belarus) by 2010, was 42% globally and ranged from 9% to 92% by region. Rotavirus vaccine and pneumococcal conjugate vaccine (PCV) had been introduced in 28 and 55 countries, respectively; however, too few countries reported data to permit robust estimates of global or regional coverage. Among the 38 countries with reported coverage for the third dose of PCV by 2010, a total of 24 (63%) had estimated coverage of ≥80%, including 17 (45%) with coverage of ≥90%.


Reported by
Dept of Immunization, Vaccines, and Biologicals, World Health Organization, Geneva, Switzerland. United Nations Children's Fund (UNICEF), New York, New York. Global Immunization Div, Center for Global Health, CDC. Corresponding contributor: Susan Goldstein, sgoldstein@cdc.gov, 404-718-8713.


Editorial Note
In 2010, an estimated 109.4 million infants worldwide had received at least 3 doses of DTP vaccine, a slight increase compared with the 108.5 million estimated by WHO and UNICEF in 2009. However, approximately 19.3 million children worldwide did not receive some or all routinely recommended childhood vaccines, leaving them susceptible to vaccine-preventable causes of disease and death. Approximately half of these undervaccinated children live in one of only three countries, and nearly two thirds live in 10 countries, underscoring the need to prioritize efforts in those countries with the highest numbers of unvaccinated children.

Among the 130 countries that met the 2010 GIVS target of ≥90% national DTP3 coverage, 111 (58%) of 193 countries sustained ≥90% coverage during 2008--2010.§ The number of countries achieving ≥80% DTP3 coverage in every district increased from 48 (25%) in 2009 to 59 (31%) in 2010 (5) but falls far short of the GIVS target for all countries to achieve this target by 2010. High national vaccination coverage, however, might obscure subpopulations with low coverage; these groups are susceptible to sustained disease transmission after an importation. During 2010, for example, a substantial increase in reported measles cases occurred in several European countries with reported MCV1 coverage levels of 90%--97% (6). In Africa, measles outbreaks of 100 or more cases were reported in 28 (61%) of 46 countries during 2009 and 2010, accounting for approximately 166,000 measles cases (7). Estimated MCV1 coverage in 2010 ranged from 46% to 94% in these countries and was 90% or higher in seven countries.

By 2010, the majority of countries had introduced HepB and Hib vaccines. As would be expected, in those countries that introduced combination vaccines containing DTP, HepB, and Hib antigens, coverage with HepB3 and Hib3 was similar to that for DTP3 within the first few years of introduction. However, for the newer monovalent vaccines, such as rotavirus vaccine and PCV, coverage will need to be closely monitored.
Administrative vaccination coverage data are more timely and easier to collect than other types of coverage data; however, the reporting of vaccine doses administered and census data are not always accurate, which can overestimate or underestimate coverage (8). WHO recommends that countries conduct regular vaccination coverage surveys to validate reported administrative coverage (4). Although surveys more closely reflect actual coverage, they are costly and difficult to conduct, and because data are collected retrospectively, surveys cannot be used for immediate assessment of immunization programs and decision-making. A WHO advisory committee is evaluating methods to improve the validity of the WHO/UNICEF coverage estimates (9). Despite improvements in global routine vaccination coverage during the past decade (3), there continue to be regional and local disparities in vaccination coverage resulting from limited resources, competing health priorities, poor health system management, and inadequate monitoring and supervision. Recognizing that vaccination is one of the most cost-effective means of preventing disease, the Decade of Vaccines Collaboration, a partnership among WHO, UNICEF, the Bill and Melinda Gates Foundation, and other global immunization partners, was launched in December 2010.¶ This collaboration will develop a global vaccination action plan focusing on increasing delivery of and expanding global access to vaccines, enhancing public and political support for vaccines and vaccination programs, and promoting vaccine-related research and development. In addition to ensuring that all children are fully vaccinated, strengthening routine vaccination programs will provide the infrastructure and platform for the sustained success of the global polio eradication and measles elimination initiatives, the global introduction of new and underutilized vaccines, and the implementation of other priority child health interventions.

References
1.Keja K, Chan C, Hayden G, Henderson RH. Expanded Programme on Immunization. World Health Stat Q 1988;41:59--63.
2.World Health Organization, UNICEF. Global immunization vision and strategy 2006--2015. Geneva, Switzerland: World Health Organization; 2005. Available at http://www.who.int/vaccines-documents/docspdf05/givs_final_en.pdf . Accessed November 1, 2011.
3.CDC. Global routine vaccination coverage, 2009. MMWR 2010;59:1367--71.
4.Burton A, Monasch R, Lautenbach B, et al. WHO and UNICEF estimates of national infant immunization coverage: methods and processes. Bull World Health Organ 2009;87:535--41.
5.World Health Organization. Immunization. WHO Vaccine Preventable Diseases Monitoring System---immunization indicators selection center. Geneva, Switzerland: World Health Organization; 2011. Available at http://apps.who.int/immunization_monitoring/en/globalsummary/indicatorselect.cfm. Accessed November 1, 2011.
6.EUVAC.net. Measles surveillance annual report 2010. Copenhagen, Denmark: Statens Serum Institute; 2011. Available at http://www.euvac.net/graphics/euvac/pdf/annual_2010.pdf . Accessed November 1, 2011.
7.CDC. Measles outbreaks and progress toward measles preelimination---African Region, 2009--2010. MMWR 2011;60:374--8.
8.Murray CJL, Shengelia B, Gupta N, Moussavi S, Tandon A, Thieren M. Validity of reported vaccination coverage in 45 countries. Lancet 2003;362:1022--7.
9.World Health Organization. Report on the WHO Quantitative Immunization and Vaccines Related Research (QUIVER) Advisory Committee Meeting, Geneva, 13--15 October 2009. Geneva, Switzerland: World Health Organization; 2010. Available at http://whqlibdoc.who.int/hq/2010/who_ivb_10.04_eng.pdf . Accessed November 1, 2011.

* Additional information available at http://www.who.int/entity/immunization_monitoring/data/coverage_estimates_series.xls .
† Among 156 (81%) member states that routinely administer Bacille Calmette-Guérin vaccine for tuberculosis.
§ Additional information available at http://www.who.int/entity/immunization_monitoring/data/coverage_estimates_series.xls .
¶ Additional information available at http://www.dovcollaboration.org/.


Global Routine Vaccination Coverage, 2010