2022-07-05-世界卫生组织-Immunization_Burundi_2022_country_profile_19页_395kb

WHO and UNICEF National Immunization Coverage Estimates Summary

Core Content

WHO and UNICEF jointly estimate national immunization coverage levels to provide a more accurate reflection of immunization system performance. These estimates are based on data from various sources, including administrative reports, official assessments, and survey results. The estimates are not derived from arbitrary adjustments but are instead based on empirical data, with special attention given to potential biases and inconsistencies. In cases where data are missing, interpolation is used to estimate coverage levels for the missing years.

Key Immunization Coverage Indicators

• BCG: Percentage of births who received one dose of the Bacillus Calmette Guerin vaccine.
• DTP1 / DTP3: Percentage of surviving infants who received the 1st or 3rd dose of diphtheria and tetanus toxoid with pertussis containing vaccine.
• Pol3: Percentage of surviving infants who received the 3rd dose of polio-containing vaccine (either oral or inactivated).
• IPV1: Percentage of surviving infants who received at least one dose of inactivated polio vaccine (IPV). In countries using only IPV, it corresponds to the first dose.
• MCV1 / MCV2: Percentage of surviving infants who received the 1st or 2nd dose of measles-containing vaccine, based on the nationally recommended schedule.
• RCV1: Percentage of surviving infants who received the 1st dose of rubella-containing vaccine. Based on the first measles-rubella combination vaccine dose, not on national reports.
• HepBB: Percentage of births who received a hepatitis B vaccine within 24 hours of delivery. Only estimated for countries with a universal birth dose policy.
• HepB3: Percentage of surviving infants who received the 3rd dose of hepatitis B vaccine.
• Hib3: Percentage of surviving infants who received the 3rd dose of Haemophilus influenzae type b vaccine.
• RotaC: Percentage of surviving infants who received the final recommended dose of rotavirus vaccine (either 2nd or 3rd dose, depending on vaccine).
• PcV3: Percentage of surviving infants who received the 3rd dose of pneumococcal conjugate vaccine. May reflect two doses prior to 1 year in some countries.
• YFV: Percentage of surviving infants who received one dose of yellow fever vaccine in countries where it is part of the national schedule or recommended in at-risk areas.

Grade of Confidence (GoC)

The GoC indicates the level of empirical support for the estimates. It is not a judgment of data quality but rather the degree of support from:

• R+: Supported by reported data.

• D+: Supported by an independent denominator from the World Population Prospects: 2022 revision.

• S+: Supported by at least one survey within 2 years.

• GoC=R+ D+: Supported by both reported data and an independent denominator.

• GoC=R+ S+ D+: Supported by reported data, survey, and an independent denominator.

• GoC=R+ D+: Supported by reported data and an independent denominator, but no survey.

• GoC=R+: Supported by reported data only.

Data Sources

• Administrative Coverage: Based on data from national authorities and health service providers. May be biased due to inaccurate numerator or denominator data.
• Official Coverage: Estimated by national authorities, possibly using a combination of administrative, survey, or other data sources.
• Survey Coverage: Based on population-based household surveys of children aged 12-23 or 24-35 months, using vaccination history or caregiver recall.

Key Observations from the Data Tables

• 2021: Administrative coverage declined due to revised birth and surviving infant data, leading to a 17% increase in target population. WHO and UNICEF await results from a planned 2022 survey.
• 2020: A one-month vaccine stock-out was reported at national and subnational levels.
• 2019: Data were provisional, with challenges in the administrative recording and reporting system.
• 2018: Coverage based on national government data.
• 2017: Supported by survey data, with a high GoC.
• 2016: Supported by survey data, with a high GoC.
• 2015: Supported by survey data, with a high GoC.
• 2014: Supported by survey data, with a high GoC.
• 2013: Inconsistent relationship between births and surviving infants, suggesting possible underestimation.
• 2012: Official estimate based on preliminary survey results.
• 2011: Based on interpolation between reported data and a survey. Reported data were excluded due to exceeding 100%.
• 2010: Estimate challenged by inconsistent denominator data.

Notes and Caveats

• The estimates are not based on classical measures of uncertainty, such as confidence intervals.
• The GoC does not reflect the quality of data reported by national authorities but rather the empirical support for the estimates.
• In some years, data were excluded due to inconsistencies or exceeding 100%.
• The country is planning a national immunization coverage survey in 2022, and results are awaited for more accurate data.
• The data should be used with caution and assessed based on the specific objective of the analysis.