Ongoing decline in childhood immunisation rates sparks concerns

The new report shows that in 2023, fully vaccinated coverage rates for children overall decreased at all three standard age assessment milestones: 12 months (to 92.8%, from 93.3% in 2022 and 94.8% in 2020), 24 months (to 90.8%, from 91.0% in 2022 and 92.1% in 2020) and 60 months (to 93.3%, from 93.4% in 2022 and 94.8% in 2020).

The recent decreases come after eight years of generally increasing coverage prior to the onset of the COVID-19 pandemic.

‘While these declines are relatively modest, the ongoing decreasing trend is concerning,’ said Associate Professor Frank Beard, Associate Director, Surveillance, Coverage, Evaluation and Social Science at NCIRS.

Timeliness of childhood vaccination suboptimal

The report also shows persisting issues with delayed childhood vaccinations.

Between 2020 and 2023, the proportion of children vaccinated on time – within 30 days of the recommended age – decreased for both the second dose of diphtheria-tetanus-pertussis-containing vaccine (from 90.1% to 83.5% for non-Indigenous children and 80.3% to 74.6% for Indigenous children) and the first dose of measles-mumps-rubella-containing vaccine (from 75.3% to 67.2% for non-Indigenous children and 64.7% to 56.0% for Indigenous children).

Mixed results for adolescents and adults

Modest yet concerning ongoing declines were also observed in adolescents, despite the removal of COVID-19 pandemic-related restrictions. Between 2022 and 2023, coverage decreased for receipt of:

• at least one dose of human papillomavirus (HPV) vaccine by 15 years of age (from 85.3% to 84.2% for girls and 83.1% to 81.8% for boys)
• an adolescent dose of diphtheria-tetanus-pertussis vaccine by 15 years of age (from 86.9% overall to 85.5%)
• one dose of meningococcal ACWY vaccine by 17 years of age (from 75.9% overall to 72.8%).

The picture for adults was more varied: coverage increased for pneumococcal vaccine (from 33.8% to 37.6% for adults turning 71 years of age) but decreased for influenza vaccine across all age groups (including from 70.0% to 64.3% for adults aged 65 years and over) and shingles vaccine (from 41.3% to 41.0% for adults turning 71 years of age).  
‘Vaccination coverage is clearly suboptimal for all adult vaccines across all adult age groups,’ Associate Professor Beard said.

Strategies needed to reverse declines, experts say

Immunisation experts say a deeper understanding of the reasons for partial and under-vaccination in Australia is needed.

‘Regular monitoring of vaccination coverage is important, but it doesn’t tell us why vaccination uptake is low or declining’, said Associate Professor Beard. ‘It is therefore critical to identify the barriers to vaccination uptake and implement evidence-based approaches to address them.’

The National Vaccination Insights project is generating insights on vaccination barriers and drivers to build evidence to inform future strategies to increase the uptake and timeliness of vaccination in Australia.

The first output from the multi-stage project – findings from a first-of-its-kind, nationally representative survey to understand what motivates adults to get an influenza vaccine – were released earlier this month.

‘Such insights will help inform strategies aimed at reversing these downward trends and protecting more Australians from the serious and sometimes life-threatening infections that can result from vaccine preventable diseases,’ Associate Professor Beard said.

Although vaccination coverage in Australia is ‘still relatively high by global standards’, Associate Professor Beard concluded, ‘the findings from this latest coverage report remind us we can’t be complacent’.