These immunization coverage data are taken from a range of household survey sources, especially the Expanded Programme on Immunization (EPI) cluster survey, the UNICEF Multiple Indicator Cluster Survey (MICS), and the Demographic and Health Survey (DHS). The data include, for each country and survey, the period of data collection, vaccine, type of evidence of immunization, age, sex, coverage, and sample size. These data are used, along with administrative data and official country immunization coverage estimates reported to the WHO and UNICEF, to inform the WHO and UNICEF adjusted estimates.