Measuring vaccine coverage

Why do we measure vaccine coverage? First, measuring vaccine coverage allows us to determine whether the immunisation program we have in place is working, that is, are children actually being vaccinated. Second, a measure of coverage allows us to establish if enough children are being vaccinated so that transmission of diseases will be interrupted. Finally, calculation of coverage at a local level allows us to identify specific areas of low coverage so that measures to improve coverage can be appropriately targeted. 

Detailed exploration and monitoring of vaccine coverage data is critical to underpin efforts to achieve and maintain high coverage in children, adolescents and adults. NCIRS plays a preeminent role in the analysis and reporting of data from the Australian Immunisation Register (AIR) and the use of these data for research, surveillance and program evaluation. NCIRS is able to download de-identified data from AIR every week.

Australian Immunisation Register

AIR is administered by Services Australia, which also administers Medicare. It has 3 main functions: 

  • to record vaccines given, both on the National Immunisation Program (NIP) Schedule and privately, to people of all ages in Australia from birth to death
  • to provide immunisation status information to parents and providers 
  • to provide a tool for monitoring vaccine coverage by age, vaccine, Aboriginal and Torres Strait Islander status and region.

The register was initially established as the Australian Childhood Immunisation Register (ACIR) on 1 January 1996, and included all children under the age of 7 years enrolled in Medicare. Participation in the ACIR was opt-out, so it constituted a nearly complete population register, as approximately 99% of children are registered with Medicare by 12 months of age. Since 2001, immunisations given overseas may be recorded if a provider endorses their validity. From 30 September 2016, the ACIR became the AIR, recording vaccinations given to people of all ages. From 1 July 2021, vaccination providers are required to report all NIP vaccines administered to AIR, along with all COVID-19 and influenza vaccines.

Australian Immunisation Register - for health professionals 

Australian Immunisation Register - for individuals

Measuring vaccine coverage using AIR 

Vaccine coverage is usually expressed as the proportion or prevalence (%) of complete immunisation by particular assessment ages. Coverage data are usually provided for each major vaccine type and for all vaccines due at a number of age milestones. In Australia, childhood immunisation aged milestones are set at:

  • 12 months (for vaccines due at 6 months)
  • 24 months (for vaccines due at 12 and 18 months)
  • 60 months (for vaccines due at 4 years).

A set number of vaccine types and doses are due at each of these milestones. A detailed description of the methods used for calculating coverage at the population level can be found in our latest national annual immunisation coverage report.

In 2017, NCIRS, with support from Services Australia and state and territory health departments, undertook a national study to assess the effectiveness of data transfer to AIR and identify ways to improve it. This study represents the first attempt at the national level since 2001 to systematically audit the accuracy of AIR data. The study was funded by the Australian Government Department of Health and Aged Care.

Annual immunisation coverage reports, Australia

NCIRS produces annual national immunisation coverage reports to highlight important trends and issues in vaccination coverage in Australia. These reports provide a detailed summary of vaccine coverage at standard milestone ages, coverage for vaccines not included in standard coverage assessments, timeliness of vaccination, vaccine coverage for Aboriginal and Torres Strait Islander children, small area vaccine coverage data, vaccination coverage at earlier milestone ages, and adult and adolescent vaccine coverage data.

2023 

  • 2023 annual immunisation coverage report can be viewed here
  • Key findings - 2023 annual immunisation coverage report can be viewed here

2022 

  • 2022 Annual immunisation coverage report can be viewed here
  • Key findings - 2022 Annual immunisation coverage report can be viewed here

2021 

  • 2021 Annual immunisation coverage report can be viewed here
  • Key findings - 2021 Annual immunisation coverage report can be viewed here

2020 

  • 2020 Annual immunisation coverage report can be viewed here
  • Key findings - 2020 Annual immunisation coverage report can be viewed here

2019

  • 2019 Annual immunisation coverage report can be viewed here
  • Key findings - 2019 Annual immunisation coverage report can be viewed here

2018

  • 2018 Annual immunisation coverage report can be viewed here
  • Key findings - 2018 Annual immunisation coverage report can be viewed here

2017

  • 2017 Annual immunisation coverage report can be viewed here

2016

  • 2016 Annual immunisation coverage report can be viewed here 
  • Summary of key findings can be viewed here 

You will need Adobe Acrobat Reader to access these files.

Refer also to Reports section. 

Previous reports

Annual Immunisation coverage reports for Australia since 2007 can be accessed here.

Annual immunisation coverage reports, New South Wales

NCIRS also produces annual immunisation coverage reports for New South Wales. These can be accessed here.

AIR data transfer study

The AIR data transfer study is the first attempt at the national level since 2001 to systematically audit the accuracy of AIR data. In 2016 the Australian Government Department of Health and Aged Care (Health) funded NCIRS to undertake, with support from Services Australia and state and territory health departments, a national study to assess the effectiveness of data transfer to AIR and identify ways to improve it. On the basis of our findings, the most influential areas in which data recording, transfer and handling could be improved to optimise the effectiveness of data transfer to AIR include:

  1. data entry for all methods of transfer to AIR
  2. processes for transfer of vaccination encounter information to AIR
  3. data management to reduce duplicate records
  4. engagement with and enhancing support to immunisation providers.

Access 2018 AIR data transfer study here

Vaccine coverage estimates 

The latest vaccine coverage estimates calculated from AIR are available here.

Immunisation coverage data sources

A document outlining available immunisation coverage data sources is available here. This information may be useful in identifying and planning immunisation activities and strategies.

Last updated October 2024