Vaccine Coverage Indicators

A high level of vaccine coverage sustained over many years is required to achieve population level control of vaccine targeted HPV types, and in the long-term, cervical cancer elimination (1,2). For the purposes of monitoring coverage over time and comparing across countries, which vary in their age of vaccination within the range 9-14 years, WHO recommends measuring ‘HPV vaccination coverage achieved by age 15 years' (3).

This indicator measures the proportion of the population turning 15 years in the reporting year who have received one (or more) HPV vaccine doses by age 15, noting that Australia moved to a single dose program in 2023 based on evidence of strong protection from one dose. Prior to 2023, the recommended schedule in Australia was either two correctly spaced doses (2018-2022) or three correctly spaced doses (2007-2017).

The WHO target relates to female-only programs, which are the most cost-effective option. Australia vaccinates both girls and boys and has adopted a 90% target for both sexes (4). Modelling suggests the same impact on HPV burden as achieving 90% coverage in girls only could be achieved with 80% coverage of both sexes (5).

Nationally, in the cohort who turned 15 years old in 2023, HPV vaccination coverage was 83.0% (84.2% in females and 81.8% in males). This represents a continuing decline from the historical peak in the 2020 cohort (85.7%, female 86.6%, male 84.9%). Coverage was lower amongst Indigenous adolescents, falling below 80% overall, at 77.9% (females 80.9%, males 75.0%) (reduced from 2022 cohort by 2.6% (female 2.1%, male 3.1%)) than non-Indigenous adolescents (83.2% overall; female 84.4%, male 82.1%) (reduced from 2022 cohort by 1.2% (female 1.1%, male 1.3%)).  This was a decline from the historical peak in Indigenous adolescents, also achieved in the 2020 cohort (females 87.8%, males 83.0%) (Figure 5.1).

There was a continuing increase in disparity of coverage in 2023 between those resident in the lowest socioeconomic quintile areas compared to those in the highest quintile, growing to 6.5 percentage points (increased from 2022 when it was 4.6 percentage points) driven by larger falls in coverage in the lowest socioeconomic areas than in the highest. For the 2023 (15 year old) cohort, who turned 13 years in 2021 and would have been impacted by pandemic-related school closures and health service disruptions, the disparity was wider in boys (5.4 percentage points) than in girls (3.8 percentage points) (noting the disparity was only 1.2 in the 15 year old female 2020 cohort and 2.2 in the 15 year old male 2020 cohort).  

In 2023 coverage fell across every remoteness area classification, falling below 80% for 15 year olds in very remote areas (76.4%; 78.2% in females and 74.7% in males) and for males in remote areas (79.2%). Coverage remained above 80% in most jurisdictions in both sexes, the exceptions being amongst males in Queensland (79.0%) and in the NT where overall coverage fell to 75.4% (down 4.5% since 2022) with male coverage falling to 72.5% and female coverage falling to 78.3%.   

Socioeconomic and regional disparities were wider amongst Indigenous adolescents than in the whole cohort. There was substantial variation in coverage amongst Indigenous adolescents by jurisdiction, with coverage in females ranging from 66.4% in SA to 91.7% in the ACT and coverage in males ranging from 59.2% in SA to 91.7% in the ACT (Figure 5.2). Among Indigenous males, coverage in 2022 was below 80% in all but two jurisdictions (Tas and NSW). Among Indigenous females, coverage in all groups showed progressive falls in 2021, 2022 and 2023. Previous disparities have re-emerged such that, rather than having the highest national coverage as in 2018-2020, Indigenous females now have lower coverage than non-Indigenous males (Figure 5.3).

Source: Australian Immunisation Register (AIR) data, as at 2nd February 2024 for 2023 data, sourced from NCIRS.

Updated data are for the 15 year old cohort in 2023 (i.e. those born 1 Jan 2008 - 31 Dec 2008) and only includes HPV vaccinations administered prior to their 15th birthday. 

Aboriginal or Torres Strait Islander identification was based on whether a person had ever self-reported their status, as recorded in the Australian Immunisation Register.

In 2023, HPV vaccine coverage continued to decline from it's peak in 2020, falling to 83.0% but with increasing numbers of subgroups falling below 80% coverage. Inequity in coverage continues to increase by available demographic variables notably for Indigenous adolescents, very remote and remote areas, and by jurisdiction of residence, and now need to be urgently addressed to prevent further falls.  Modelling has suggested, for countries like Australia that vaccinate males as well as female students, elimination of vaccine-preventable HPV types is likely achievable in the long term with a sustained coverage of 80% (or more) (5). Concerningly coverage data comparing HPV coverage in 13 year olds (i.e. closer to age of vaccination, which occurs routinely through the school based immunisation program at age 12-13 years in Year 7) between 2022 and 2023, when a single-dose vaccine schedule was introduced, shows that coverage declined between the two cohorts for Indigenous adolescents (from 64.7% in 2022 to 60.2% in 2023) (6,7), suggesting an ongoing issue rather than just a decline in cohorts directly impacted by pandemic disruptions to school programs. It will be important to investigate to what extent the schedule change may have reduced real opportunities for in-school vaccination or whether the decline is due to more widespread trends in vaccination uptake generally. Vaccine coverage in Australia has declined in the post-pandemic period across the adolescent vaccine schedule, with factors like fewer school visits and higher absenteeism hypothesised to be behind gradual, incremental declines seen in adolescent vaccination (6). Globally childhood immunisation coverage has also stalled and not yet returned to 2019 levels, with measles outbreaks occurring in many countries, reflecting 'ongoing challenges with disruptions in healthcare services, logistical challenges, vaccine hesitancy and inequities in access to services' (8). 

Other high-income countries are also struggling to regain HPV vaccine coverage post pandemic disruptions. A post pandemic decline in HPV vaccine uptake has been noted in the US in 2023, on a background of continuous year on year increases in coverage pre-pandemic (9). HPV vaccine coverage in England has not yet recovered to pre-pandemic levels, with current coverage in Year 8 girls in the target cohort at 71.3%, 16.7% lower than pre-pandemic (10).In Canada, data suggests a 15-81% decline in HPV course completion post pandemic across the country (11). While single dose vaccination creates the opportunity for easy catch up in multiple settings, including in school, primary care and community settings such as pharmacies, further promotion of its availability and desirability appears to be urgently needed. Data are not yet available reporting coverage for other priority populations such as people who are part of culturally and linguistically diverse communities, those living with disability, or those who are medically at higher risk from HPV (eg immunosuppressed), although work is underway to develop methods for monitoring coverage in these groups through data linkage (the INCLUDE study) (12).  

It should be noted that this indicator is designed to monitor achievement of coverage by a certain age over time rather than highest coverage ever achieved in a birth cohort (for example by including doses delivered at age 15 or afterwards). Data suggests that coverage by birth cohort currently peaks at age 19 years in Australia (6). There is now an additional opportunity to improve coverage further, catch up the pandemic and post-pandemic cohorts, and mitigate the dilution of coverage by immigration in the young adult age group, through the extended funded single dose catch up introduced in 2023 through to age 25 years inclusive. 

1 World Health Organization. Global strategy to accelerate the elimination of cervical cancer as a public health problem. 2020. Available at: https://www.who.int/publications/i/item/9789240014107 

2 Simms KT, Steinberg J, Caruana M, et al. Impact of scaled up human papillomavirus vaccination and cervical screening and the potential for global elimination of cervical cancer in 181 countries, 2020-99: a modelling study. Lancet Oncology 2019; 20(3): 394-407. 

3 Bruni L, Saura-Lazaro A, Montoliu A, et al. HPV vaccination introduction worldwide and WHO and UNICEF estimates of national HPV immunization coverage 2010-2019. Preventive Medicine 2020: 106399. 

4 Australian Centre for the Prevention of Cervical Cancer. National Strategy for the Elimination of Cervical Cancer in Australia. November 2023. Available at: https://www.health.gov.au/resources/publications/national-strategy-for-the-elimination-of-cervical-cancer-in-australia?language=en 

5 Brisson M, Benard E, Drolet M, et al. Population-level impact, herd immunity, and elimination after human papillomavirus vaccination: a systematic review and meta-analysis of predictions from transmission-dynamic models. Lancet Public Health 2016; 1(1): e8-e17.

6 Hull B, Hendry A, Macartney K, Beard F. Annual immunisation coverage report 2023. National Centre for Immunisation Research and Surveillance 2024. Available at:  https://ncirs.org.au/sites/default/files/2024-10/NCIRS%20Annual%20Immunisation%20Coverage%20Report%202023.pdf 

7 Hull B, Hendry A, Dey A, Brotherton J, Macartney K, Beard F. Annual immunisation coverage report 2022. National Centre for Immunisation Research and Surveillance 2023. Available at: https://ncirs.org.au/sites/default/files/2024-10/NCIRS%20Annual%20Immunisation%20Coverage%20Report%202023.pdf 

8 World Health Organization. Global childhood immunization levels stalled in 2023, leaving many without life-saving protection. 15 July 2024 Joint News Release WHO/UNICEF. Geneva/New York.  Available at: https://www.who.int/news/item/15-07-2024-global-childhood-immunization-levels-stalled-in-2023-leaving-many-without-life-saving-protection 

9 Pingali C, Yankey D, Chen M, et al. National Vaccination Coverage Among Adolescents Aged 13–17 Years — National Immunization Survey-Teen, United States, 2023. Morbidity and Mortality Weekly Report. 2024;73:708–714. DOI: http://dx.doi.org/10.15585/mmwr.mm7333a1.

10 UK Health Security Agency. Official Statistics. Human papillomavirus (HPV) vaccination coverage in adolescents in England: 2022 to 2023. Published 23 January 2024. Available at: https://www.gov.uk/government/statistics/human-papillomavirus-hpv-vaccine-coverage-estimates-in-england-2022-to-2023/human-papillomavirus-hpv-vaccination-coverage-in-adolescents-in-england-2022-to-2023

11 Perez C. Recent Evidence confirms that Canada’s school-based human papillomavirus (HPV) vaccination are greatly impacted due to COVID-19 Pandemic: Opportunities to Increase HPV vaccine rates [e-letter]. 3rd Dec 2023. Canadian Medical Association Journal. Available at: https://www.cmaj.ca/content/193/37/E1467/tab-e-letters 

12 The INCLUDE Study: Cervical cancer prevention for all. Webpage; Kirby Institute UNSW. Last accessed 23/08/2024. Available at: https://www.kirby.unsw.edu.au/research/projects/include-study