Annual Immunisation Coverage Report 2022.

OVERVIEW

We analysed Australian Immunisation Register (AIR) data, predominantly for National Immunisation Program funded vaccines, as at 2 April 2023 for children, adolescents and adults, focusing on the calendar year 2022 and on trends from previous years. This report aims to provide comprehensive analysis and interpretation of vaccination coverage data to inform immunisation policy and programs.

CHILDREN

Fully vaccinated coverage in Australian children in 2022 was 0.6-1.1 percentage points lower than in 2021 at the 12-month (93.3%), 24-month (91.0%) and 60-month (93.4%) age assessment milestones. This follows the 0.6-0.8 percentage point decrease at the 12- and 60-month milestones between the 2020 and 2021 reports, which came after eight years of generally increasing coverage. Due to the lag time involved in assessment, fully vaccinated coverage figures for 2021 and 2022 predominantly reflect vaccinations due in 2020 and 2021, respectively, and therefore reflect impacts of the first two years of the coronavirus disease 2019 (COVID-19) pandemic. Fully vaccinated coverage in Aboriginal and Torres Strait Islander (hereafter, respectfully, Indigenous) children was 1.2-2.2 percentage points lower in 2022 than in 2021 at the 12-month (90.0%), 24-month (87.9%) and 60-month (95.1%) milestones, indicating differential impacts of the pandemic. However, at the 60-month milestone, coverage in Indigenous children was 1.7 percentage points higher than in children overall. There were also clear pandemic impacts on on-time (within 30 days of recommended age) vaccination. On-time coverage of both the second dose of diphtheria-tetanus-pertussis and the first dose of measles-mumps-rubella-containing vaccines decreased progressively from mid-2020 onwards (6 and 12 percentage point falls, respectively) before recovering partially in the second half of 2022, with decreases 1.5-2.3 percentage points greater in Indigenous than non-Indigenous children, from an already close to 10 percentage points lower pre-pandemic baseline.

ADOLESCENTS

Of adolescents turning 15 years in 2022, a total of 85.3% of girls and 83.1% of boys (83.0% and 78.1% of Indigenous girls and boys) had received at least one dose of human papillomavirus (HPV) vaccine by their fifteenth birthday, 0.9-1.3 percentage points lower than in 2021 (2.5-3.1 percentage points for Indigenous adolescents), also reflecting pandemic impacts. It will be important to monitor coverage with the single-dose HPV vaccine schedule - which was implemented from February 2023 - to ensure that it is sustained (ideally, increasing) and equitable, given that coverage in 2022 was 5-6 percentage points lower in adolescents in socioeconomically disadvantaged and remote areas. By 31 December 2022, coverage for an adolescent dose of diphtheria-tetanus-acellular pertussis vaccine in adolescents turning 15 years in 2022 was 86.9% (82.6% for Indigenous adolescents) and coverage for an adolescent dose of meningococcal ACWY vaccine in those turning 17 years was 75.9% (65.6% for Indigenous adolescents). Ongoing adolescent coverage gaps warrant tailored strategies to achieve higher vaccine uptake.

ADULTS

Zoster vaccination coverage in 2022 was 41.3% in adults turning 71 years (37.7% in Indigenous adults), 2.6 (3.6) percentage points higher than in 2021, and was highest in adults turning 75 years (54.6% and 54.0%), reflecting a combination of vaccination at 70 years and catch-up at older ages. Coverage of 13-valent pneumococcal conjugate vaccine (13vPCV) was 33.8% in adults turning 70 years in 2022 (37.7% in Indigenous adults), 9.9 (12.6) percentage points higher than in 2021. These increases may be partly due to more complete reporting following the introduction of mandatory reporting to the AIR in mid-2021. Influenza vaccination coverage in adults in 2022 increased with increasing age, reaching 73.0% in the ≥ 75 years age group. Coverage was higher in 2022 than in 2021 across all adult age groups, with the proportionate increase since 2019 four- to five-fold higher in those aged < 65 years than in those aged ≥ 65 years. This likely reflects increased completeness due to mandatory reporting, with coverage previously substantially underestimated in younger adults.

CONCLUSIONS

Vaccination coverage in children and adolescents decreased modestly in 2022, reflecting impacts of the COVID-19 pandemic, but remained relatively high in global terms. The decrease in coverage was greater in Indigenous children and adolescents, with timeliness of vaccination an ongoing issue exacerbated by the pandemic. While adult coverage increased in 2022 - likely, in part, due to the introduction of mandatory reporting to AIR resulting in more accurate estimates - it remains suboptimal. Limited evidence suggests the lower coverage in children and adolescents is due to a combination of acceptance and access factors. Particularly given the evidence that these modest declines in coverage have continued into the first half of 2023, further exploration is needed to better understand these factors and to inform approaches to effectively address barriers and increase vaccine uptake.