2022-07-05-世界卫生组织-Immunization_Niger_the_2022_country_profile_20页_415kb

Summary of WHO and UNICEF Immunization Coverage Estimates for Niger (2021 Revision)

Based on data received as of July 7, 2022, with the next revision due July 15, 2023.

The report provides country-specific estimates of immunization coverage in Niger for various vaccines from 2010 to 2021, based on reported data, surveys, and administrative records. Estimates are developed collaboratively by WHO and UNICEF and are not adjusted across countries.

Methodology Overview

• Estimates use a grade of confidence (GoC) to indicate reliability: ••• for high support, •• for some support, • for low support. GoC reflects empirical support but does not judge data quality.
• Data sources include national government reports, surveys, administrative data, and independent denominator recalculations. Adjustments are made for issues like stock-outs or denominator inaccuracies.
• Uncertainty is not quantified with statistical intervals, and estimates should be interpreted cautiously based on the objective.

Vaccines Covered and Key Trends

• BCG: Coverage for tuberculosis prevention fluctuates (average ~80% recent years), with stock-outs in several years (e.g., 2011–2013 low due to shortages). Min: ~43% (2013 for Pol3), max: ~95%.
• DTP (Diphtheria, Tetanus, Pertussis): Initial dose (DTP1) and third dose (DTP3) show consistent coverage around 70–95%, often affected by stock-outs and administrative data biases. DTP3 is equivalent to Pol3 for polio vaccines.
• Polio (Pol3): Coverage ranges widely due to stock-outs; e.g., dipped to ~40% in some years. Highest estimates around 90–95%, but reliability low.
• IPV (Inactivated Poliovirus Vaccine): Introduced in 2015; coverage estimates from 2016–2021 show low initial values (~27–74%), with better alignment later.
• Measles Containing Vaccines (MCV1 and MCV2): Coverage for first and second doses varies; recent years ~60–85%, but stock-outs common.
• Rubella Containing Vaccine (RCV1): Coverage consistently low or unreliably estimated with no supporting data.
• Hepatitis B (HepBB and HepB3): Birth dose HepBB missing data; third dose HepB3 coverage similar to DTP trends, affected by supply issues.
• Hib (Haemophilus influenzae type B): Third dose Hib3 coverage mirrors DTP trends, with adjustments for recall bias in surveys.
• RotaC and PcV3: Coverage introduced around 2014–2015, with rates varying; RotaC averages ~19–85%, PcV3 ~13–84%.
• Yellow Fever Vaccine (YFV): Estimation based on related vaccines or surveys, prone to stock-out issues.

Common Challenges

• Stock-outs of vaccines (e.g., for Polio, Rotavirus) directly reduce reported coverage.
• Administrative data often understates target populations or has inaccuracies.
• Surveys sometimes show biases from recall errors, requiring adjustments.
• Many estimates for older vaccines or periods have low GoC, indicating potential misrepresentation.

Conclusion

Immunization coverage in Niger has shown improvements but remains inconsistent, hindered by supply chain disruptions and data quality issues. Recent estimates (2018–2021) generally range from 70% to 90%, but significant annual variations exist. For accurate assessments, users should consult the GoC and referenced data sources. Further information available at: WHO Immunization Data Listing and UNICEF Data.