2023-07-16-世界卫生组织-Immunization_Algeria_2023_country_profile_20页_374kb

WHO and UNICEF Immunization Coverage Estimates for Algeria (2022 Revision)

Introduction

WHO and UNICEF provide estimates of national immunization coverage for Algeria based on data received as of June 26, 2023. This report analyzes data sources, estimation methods, and coverage trends for various vaccines over the period 2002–2023.

Key Estimation Methodology

• Data Sources: Estimates incorporate administrative reports (from health services), survey-based data (e.g., Multiple Indicator Cluster Surveys), interpolation for missing years, and empirical data corrections.
• Grade of Confidence (GoC): Reflects the empirical support for estimates and is categorized as:
  • ★★★ High support (well-supported with minimal risk).
  • ★★ Medium support (data accepted but with potential challenges).
  • ★ Low support (data questionable or accepted empirical data absent).
• Confidentiality: No underlying probability models, so uncertainty measures like confidence intervals are not provided. Estimates should be used cautiously due to potential data biases.

Overview of Immunization Coverage

• The estimates cover key vaccines such as BCG, DTP, poliovirus, measles, hepatitis B, influenza type B, Hib, and pneumococcal conjugate vaccines.
• Coverage is reported annually for each vaccine, with changes noted in the descriptions.
• Interpolation is used when data is incomplete, and official government estimates sometimes exceed administrative data without explanation.
• Most recent coverage (2022–2023) shows slight year-over-year declines for some vaccines, reflecting reliability issues in data sources.

Vaccine-Specific Highlights

• BCG: Covered at high rates (e.g., 99–100%) with consistent administrative data support.
• DTP: DTP1 and DTP3 coverages range from 77% to 97%, with challenges in data reliability for DTP2.
• Poliovirus: IPV1 coverage started in 2015, averaging around 90%, while Pol3 shows variability.
• Measles & Rubella: MCV1 and MCV2 coverages around 70–80%, dependent on survey data with interpolation for gaps.
• Hepatitis B: HepBB (birth dose) consistently high (99%+), but HepB3 and HepB3 show declines.
• Other vaccines include Hib3, RotaC, and PcV3, with data challenges and varying interpolation methods.

Limitations and Recommendations

• Data quality varies, with discrepancies between official government estimates and reported administrative coverage.
• Surveys often uncover biases, affecting accuracy for vaccines like Hib and RCV1.
• Estimates may be inaccurate due to unknown data biases; users should assess the suitability of estimates for their specific needs.
• Full data and methodology details available at: WHO and UNICEF.

Concluding Notes

For Algeria, overall immunization coverage remains substantial but experiences fluctuations, particularly for newer vaccines. Continuous monitoring through improved data collection and surveys is recommended for accurate coverage tracking.