Immunization, Vaccines and Biologicals

Immunization coverage

Survey methods

Surveys aim to estimate the levels of immunization coverage at either national or sub-national levels. They aim to either establish baseline information, to provide a comparison with administrative estimates (to verify administrative coverage data), or to satisfy the demands of the partner agencies

Although the primary objective of an immunIzation coverage survey is to provide a coverage estimate for selected vaccines (for infants and/or women), other information, which is usually not available through routine monitoring systems, can be collected simultaneously

Examples of other information that can be collected are:

  • reasons for non immunization
  • proportion of administered doses that are valid
  • coverage by categories such as gender and socio-economic status
The two main methods recommended by WHO are:
  • the EPI cluster survey (WHO methodology)
  • the Lot Quality Assurance (LQA) technique