Immunization Analysis and Insights
The Immunization Analysis & Insights Unit is a data hub and analytics engine for immunization data and performs analytics. The unit supports the work of other technical units within the department of Immunization, Vaccines and Biologicals (IVB) and drives innovation in data quality and use in countries. It also has responsibility for IVB’s global work on VPD surveillance and generating data and evidence on the public health and economic impact of vaccines.
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.