Immunization, Vaccines and Biologicals

Immunization coverage

Administrative method

In most countries "administrative coverage data" are the number of doses administered to the target population

In order to estimate percentage immunization coverage, this number is divided by the total estimated number of people in the target population

The target population groups vary from country to country and are dependent on the national immunization schedule in place

The coverage estimates calculated using the administrative method can be biased due to inaccurate numerators or denominators


Numerators may be:

  • underestimated (due to incomplete reporting from reporting units or non-inclusion of other vaccinating sources (e.g. private sector, non-governmental organizations), or
  • overestimated (due to over-reporting from reporting units e.g. inclusion of other target groups)

Denominator inaccuracies may be due to issues such as:

  • population movement
  • inaccurate census estimations or projections and/or
  • numerous sources of denominator data