2023-07-16-世界卫生组织-Immunization_Malaysia_2023_country_profile_17页_353kb

Malasyiimmunization Coverage Summary

This report provides an overview of Malaysia's national immunization coverage estimates for key vaccines based on data from WHO and UNICEF, spanning the years 2011–2022. Coverage estimates vary by vaccine type and are subject to varying degrees of certainty, often influenced by data sources (administrative, survey-based) and reporting consistency.

Key Observations:

1. Vaccine-Specific Trends

   • BCG: Maintained near universal coverage (>98%) from 2018–2022, with minor fluctuations.
   • DTP1/DTP3: Stable around 95–99% except slight declines in 2019–2022, attributed to reporting issues.
   • Polio (Pol3/OPV/IPv) and Measles/Rubella (MCV/RCV): Showed consistent high coverage (95–99% in most years) but faced challenges in data reliability due to target population adjustments.
   • HepB: Coverage fluctuated slightly, particularly in the third dose, with confidence capped due to inconsistent data.
   • Other Vaccines (IPV, Hib, Rota, Pcv): Introduced or expanded in recent years, with newer vaccines like RotaC and PcV3 showing coverage confidence limited by recent data availability.

2. Data Consistency & Confidence Grades (GoC):

   • Most estimates rely on administrative data (R+) supplemented by population surveys (S+) or adjusted demographic data (D+).
   • Higher confidence (**GoC) was rare for newer or recently introduced vaccines; limited supporting surveys left many estimates with moderate confidence (GoC).
   • Downward revisions frequently cited target population declines (≈7%) in 2019–2021, masking declines in vaccine administration.

3. Recent Trends & Methodology

   • No national household surveys available within the last 5 years per the 2022-23 survey awaited results.
   • Coverage estimation relies on reported data, with adjustments for denominator population using UN data.
   • Estimates are derived from interpolation/estimation when data is missing, which introduces uncertainty.
   • Disclosure: UNICEF/WHO data may not reflect underlying realities, and no formal confidence intervals are provided.

4. Strengths & Limitations

   • Strengths: Decades of consistent data collection; The methodology allows independent denominator checks, adding transparency to estimates.
   • Limitations: Trends are affected by declining target populations without reflecting concurrent coverage drops; estimates for newer vaccines remain data-starved (e.g., RotaC into late 2022).

Key Challenges

• Occurrence of >100% reported vaccination (often excluded) raises concerns about over-reporting or inconsistent denominator updates.
• Several estimates carry a "risk of being wrong" due to varying data quality (GoC limited to –*).
• Pockets of lower coverage exist (e.g., MCV2/Hib3) despite overall stability.

Recommendations

• National efforts should focus on verifying reported coverage against survey data and preserving sample sizes in future surveys to reduce uncertainties.
• Improved surveillance of administration rates and denominators at the sub-national level would enhance estimates.