These are important points to keep in mind when attempting to compare routine coverage estimates with survey coverage estimates.
WHO and UNICEF meet once each year to compare, for over 150 countries, the routine estimates of immunization coverage with the survey estimates and information from other sources. Their annual comparison graphs for each country can be downloaded from the following website: http://apps.who.int/immunization_monitoring/globalsummary/wucoveragecountrylist.html
