WHO and UNICEF estimates of national infant immunization coverage: methods and processes

Abstract

WHO and the United Nations Children's Fund (UNICEF) annually review data on immunization coverage to estimate national coverage with routine service delivery of the following vaccines: bacille Calmette-Guérin; diphtheria-tetanus-pertussis, first and third doses; either oral polio vaccine or inactivated polio vaccine, third dose of either; hepatitis B, third dose; Haemophilus influenzae type b, third dose; and a measles virus-containing vaccine, either for measles alone or in the form of a combination vaccine, one dose. The estimates are based on government reports submitted to WHO and UNICEF and are supplemented by survey results from the published and grey literature. Local experts, primarily national immunization system managers and WHO/UNICEF regional and national staff, are consulted for additional information on the performance of specific immunization systems. Estimates are derived through a country-bycountry review of available data informed and constrained by a set of heuristics; no statistical or mathematical models are used. Draft estimates are made, sent to national authorities for review and comment and modified in light of their feedback. While the final estimates may not differ from reported data, they constitute an independent technical assessment by WHO and UNICEF of the performance of national immunization systems. These country-specific estimates, available from 1980 onward, are updated annually.Une traduction en français de ce résumé figure à la fin de l'article. Al final del artículo se facilita una traducción al español. ‫املقالة.‬ ‫لهذه‬ ‫الكامل‬ ‫النص‬ ‫نهاية‬ ‫يف‬ ‫الخالصة‬ ‫لهذه‬ ‫العربية‬ ‫الرتجمة‬

Vaccination coverage and factors associated with adherence to the vaccination schedule in young children of a rural area in Burkina Faso

“…The coverage among the children included in our study is still lower than the national estimates: for the Nouna district, the administrative coverage was 107% in 2013, while the national coverage was 98% [28]. However, administrative coverage estimates are based on the number of vaccine doses administered to an estimated target population and very likely do not accurately reflect coverage [29]. …”

Estimating Coverage of Hepatitis B Birth Dose Vaccination: A Pilot Study in Western Pacific Countries

“…In order to validate obtained information, we extracted estimates for the percentage of We assumed that survey data are more accurate than countryreported reported data unless there are clear flaws in the survey methodology or report e.g. sample size not stated [18]. If survey data were available on delayed birth doses, i.e.…”

“…Levels and trends of immunization coverage are used (i) to monitor the performance of immunization services locally, nationally and internationally; (ii) to guide strategies for the eradication, elimination and control of vaccinepreventable diseases; and (iii) to identify areas of immunization systems that may require additional resources and focused attention. Models of vaccine-preventable disease burden frequently include immunization coverage levels among their components [18]. While coverage estimates are available for the principle recommended infant vaccines, including the third dose of hepatitis B vaccine (HepB3), estimates are not currently made for the birth dose of hepatitis B vaccine.…”

WUENIC – A Case Study in Rule-Based Knowledge Representation and Reasoning

“…Since 2000 the World Health Organization (WHO) and the United Nations Children's Fund (UNICEF) have made annual estimates of national infant immunization coverage for selected vaccines [2]. Among other uses, these estimates are used to track progress towards the Millennium Development Goal 4 of reducing child mortality.…”

“…The WHO/UNICEF working group had been applying an informal set of rules [2], before starting the project in the summer of 2009. At first, the most natural formalization seemed to be in terms of production rules.…”