SDMX Metadata Concepts

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0.a. Goal

Goal 3: Ensure healthy lives and promote well-being for all at all ages

0.b. Target

Target 3.b: Support the research and development of vaccines and medicines for the communicable and non‑communicable diseases that primarily affect developing countries, provide access to affordable essential medicines and vaccines, in accordance with the Doha Declaration on the TRIPS Agreement and Public Health, which affirms the right of developing countries to use to the full the provisions in the Agreement on Trade-Related Aspects of Intellectual Property Rights regarding flexibilities to protect public health, and, in particular, provide access to medicines for all

0.c. Indicator

Indicator 3.b.1: Proportion of the target population covered by all vaccines included in their national programme

0.e. Metadata update

2023-03-31

0.g. International organisations(s) responsible for global monitoring

World Health Organization (WHO), United Nations Children’s Fund (UNICEF)

1.a. Organisation

World Health Organization (WHO), United Nations Children’s Fund (UNICEF)

2.a. Definition and concepts

Definition:

Coverage of DTP containing vaccine (3rd dose): Percentage of surviving infants who received the 3 doses of diphtheria and tetanus toxoid with pertussis containing vaccine in a given year.

Coverage of Measles containing vaccine (2nd dose): Percentage of children who received two dose of measles containing vaccine according to nationally recommended schedule through routine immunization services in a given year.

Coverage of Pneumococcal conjugate vaccine (last dose in the schedule): Percentage of surviving infants who received the nationally recommended doses of pneumococcal conjugate vaccine in a given year.

Coverage of HPV vaccine (last dose in the schedule): Percentage of 15 years old girls who received the recommended doses of HPV vaccine. Currently performance of the programme in the previous calendar year based on target age group is used.

Concepts:

In accordance with its mandate to provide guidance to Member States on health policy matters, WHO provides global vaccine and immunization recommendations for diseases that have an international public health impact. National programmes adapt the recommendations and develop national immunization schedules, based on local disease epidemiology and national health priorities. National immunization schedules and number of recommended vaccines vary between countries, with only DTP polio and measles containing vaccines being used in all countries.

The target population for given vaccine is defined based on recommended age for administration. The primary vaccination series of most vaccines are administered in the first two years of life.

Coverage of DTP containing vaccine measure the overall system strength to deliver infant vaccination

Coverage of Measles containing vaccine ability to deliver vaccines beyond first year of life through routine immunization services.

Coverage of Pneumococcal conjugate vaccine: adaptation of new vaccines for children

Coverage of HPV vaccine: life course vaccination

2.b. Unit of measure

Percent

3.a. Data sources

National Health Information Systems or National Immunization systems

National immunization registries

High quality household surveys with immunization module (e.g. Demographic and Health Surveys (DHS), Multiple-Indicator Health Surveys (MICS), other national surveys)

3.b. Data collection method

Annual data collection through established mechanism. Since 1998, in an effort to strengthen collaboration and minimize the reporting burden, WHO and UNICEF jointly collect information through a standard questionnaire (the Joint Reporting Form) sent to all Member States http://www.who.int/immunization/monitoring_surveillance/routine/reporting/en/

3.c. Data collection calendar

Annual data collection March-May each year. Country consultation June each year

3.d. Data release calendar

15 July each year for time series 1980 – release year -1. (on 17 July 2023 estimates from 1980-2022)

3.e. Data providers

Ministries of Health, Immunization programmes, DHS and MICS websites

3.f. Data compilers

WHO and UNICEF

4.a. Rationale

This indicator aims to measure access to vaccines, including the newly available or underutilized vaccines, at the national level. In the past decades all countries added numerous new and underutilised vaccines in their national immunization schedule and there are several vaccines under final stage of development to be introduced by 2030. For monitoring diseases control and impact of vaccines it is important to measure coverage from each vaccine in national immunization schedule. A system is already in place to monitor immunization coverage for all national programmes, however direct measurement for proportion of population covered with all vaccines in the programme is only feasible if the country has a well-functioning national electronic immunization registry allowing coverage by cohort to be easily estimated. While countries will develop and strengthen immunization registries there is a need for an alternative measurement.

4.b. Comment and limitations

The rational to select a set of vaccines reflects the ability of immunization programmes to deliver vaccines over the life cycle and to adapt new vaccines. Coverage for other WHO recommended vaccines are also available and can be provided.

Given that HPV vaccine is relatively new and vaccination schedule varies from countries to country coverage estimate will be made for girls vaccinated by ag 15 and at the moment data is limited to very few countries therefore reporting will start later.

4.c. Method of computation

WHO and UNICEF jointly developed a methodology to estimate national immunization coverage form selected vaccines in 2000, and this approach has been refined and reviewed by expert committees over time. The methodology was published and reference is available under the reference section. Estimates time series for WHO recommended vaccines produced and published annually since 2001.

The methodology uses data reported by national authorities from countries administrative systems as well as data from immunization or multi indicator household surveys. The WHO/UNICEF estimates of national immunization coverage have been assessed using the Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER) checklist.

4.d. Validation

WHO and UNICEF encourage countries to review and comment on the draft coverage estimates shared following the draft production. In past years, regional or sub-regional consultations have been held during May/June to go through select country data and estimates.

4.e. Adjustments

Not applicable

4.f. Treatment of missing values (i) at country level and (ii) at regional level

  • At country level

The first data point is the first reporting year after vaccine introduction. When country data are not available interpolation is used between 2 data points and extrapolation from the latest available data point.

  • At regional and global levels

Any needed imputation is done at country level. These country values are then used to compute regional and global estimates.

4.g. Regional aggregations

Weighted average of the country-level coverage rates where the weights are the country target population sizes based on World Population Prospects: 2022 revision from the UN Population Division. All Member States from the region are included. For HPV 15 year old girls are used for calculation weighted average.

4.h. Methods and guidance available to countries for the compilation of the data at the national level

Not applicable

4.i. Quality management

Not applicable

4.j. Quality assurance

Not applicable

4.k. Quality assessment

Not applicable

5. Data availability and disaggregation

Data availability:

Coverage data for different vaccines are collected annually and reviewed by WHO and UNICEF inter agency expert group and estimates made for each country and each year. Data are published both on WHO and UNICEF web sites.

http://www.who.int/immunization/ monitoring_surveillance/routine/coverage/en/index4.html http://www.data.unicef.org/child-health/immunization

Coverage for 2021 (in %)

DTP3

MCV2

PCV3

HPV

Global

81

71

51

12

Australia and New Zealand

94

92

96

63

Central Asia and Southern Asia

86

83

45

2

Eastern Asia and South-eastern Asia

84

83

14

1

Latin America & the Caribbean

75

68

70

32

Northern America and Europe

93

91

80

37

Oceania

70

63

70

35

Sub-Saharan Africa

70

40

64

20

Western Asia and Northern Africa (M49)

88

83

56

1

Disaggregation:

Geographical location, i.e. regional and national and potentially subnational estimates

6. Comparability/deviation from international standards

Sources of discrepancies:

Countries often relay on administrative coverage data, while WHO and UNICEF review and assess data from different sources including administrative systems and surveys. Differences between country produced and international estimates are mainly due to differences between coverage estimates from administrative system and survey results.

In case the vaccine is not included in national immunization schedule the coverage from private sector vaccine delivery will not be reflected.

7. References and Documentation

Burton A, Monasch R, Lautenbach B, Gacic-Dobo M, Neill M, Karimov R, Wolfson L, Jones G, Birmingham M. WHO and UNICEF estimates of national infant immunization coverage: methods and processes. Bull World Health Organ. 2009;87(7):535-41.Available at: http://www.who.int/bulletin/volumes/87/7/08-053819/en/

Burton A, Kowalski R, Gacic-Dobo M, Karimov R, Brown D. A Formal Representation of the WHO and UNICEF Estimates of National Immunization Coverage: A Computational Logic Approach. PLoS ONE 2012;7(10): e47806. doi:10.1371/journal.pone.0047806. Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3485034/pdf/pone.0047806.pdf

Brown D, Burton A, Gacic-Dobo M, Karimov R. An Introduction to the Grade of Confidence in the WHO and UNICEF Estimates of National Immunization Coverage. The Open Public Health Journal 2013, 6, 73-76. Available at: http://www.benthamscience.com/open/tophj/articles/V006/73TOPHJ.pdf

Brown, David & Burton, Anthony & Gacic-Dobo, Marta. An examination of a recall bias adjustment applied to survey-based coverage estimates for multi-dose vaccines. 2015. 10.13140/RG.2.1.2086.2883.

Danovaro-Holliday MC, Gacic-Dobo M, Diallo MS et al. Compliance of WHO and UNICEF estimates of national immunization coverage (WUENIC) with Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER) criteria. Gates Open Res 2021, 5:77 Available at: https://doi.org/10.12688/gatesopenres.13258.1