Thu, 07/23/2020 | News

Need to expand immunisation coverage algorithm at 5 years: NCIRS report

Assessment of vaccination coverage is important to measure the success of immunisation programs and to inform policy and program changes. In Australia individual vaccine and fully vaccinated coverage for children is routinely measured at age 1, 2 and 5 years. A new immunisation coverage report, Coverage at the 2-year and 5-year milestone ages, by the National Centre of Immunisation Research and Surveillance (NCIRS) highlights the consistently lower coverage observed at the 2-year milestone and argues for the need to change the way fully vaccinated coverage is assessed at the 5-year milestone age to better reflect true coverage. 

The report, which compares coverage at the 2-year and 5-year milestone ages, found that fully vaccinated coverage at the 2-year age milestone has been lower because of changes in the National Immunisation Program schedule and the 2-year coverage assessment algorithm, which now includes one vaccine due at 6 months of age, two vaccines due at 12 months of age and three vaccines due at 18 months, whereas the algorithm used at 5 years now assesses only one vaccine due at 4 years of age. This has caused some misinterpretation and messaging issues, as many stakeholders are unaware of these discrepancies, and also makes 5-year coverage data less useful in assessing the effectiveness of the National Immunisation Program.

To address these issues, the coverage algorithm at 5 years should be expanded to include a more comprehensive range of vaccines that a child should have received by this age, suggest the report’s authors. While acknowledging that such a change may present a communications challenge, careful planning and parallel reporting could help address messaging issues, the authors say. 

Read the full report here