2022-07-13-世界卫生组织-WHO_UNICEF_Immunization_Coverage_Estimates_-_2021_revision_22页_677kb

WHO and UNICEF Joint Estimates of National Immunization Coverage are annual assessments for infant and childhood vaccines, revised in 2021 (completed on 15 July 2022) based on data from member states, surveys, and other sources as of 7 July 2022. The estimates are country-specific and involve reviewing empirical data, adjusting for biases, and interpolating missing years when necessary. The COVID-19 pandemic lowered response rates for data collection, leading to extrapolations for some countries.

Key vaccines covered include the second dose of measles-containing vaccine (MCV2), introduced in 2013 estimates, hepatitis B birth dose (added in 2013), inactivated polio vaccine (IPV, added in 2015 with evolving coverage interpretations due to pandemics), and rubella-containing vaccine (added in 2015). For some vaccines, data scarcity or timing issues affect estimate accuracy.

Data are sourced from WHO and UNICEF websites, national reports, surveys (e.g., DHS, MICS), and UN population data. Estimates are challenged in certain cases due to data quality, reporting inconsistencies, or COVID-related disruptions. Comparison with reported data shows that for DTP3 coverage in 2021, WHO estimates align with or differ from national figures, with some countries having calibrated or unsupported estimates due to administrative errors or coverage gaps. Annual reviews adjust estimates based on new data and country feedback.

The methodology references specific publications on computational logic and grades of confidence, and future refinements are planned, particularly for IPV coverage under changing global health strategies. No warranty is given for the estimates, and readers should interpret data independently.