3.02 Immunisation

Key facts

Why is it important?

Immunisation is highly effective in reducing morbidity and mortality caused by vaccine-preventable diseases. Childhood vaccination for diphtheria was introduced in Australia in 1932 and the use of vaccines to prevent tetanus, pertussis (whooping cough) and poliomyelitis became common in the 1950s. This was followed by vaccines for measles, mumps and rubella in the 1960s, and later vaccines for hepatitis B, Haemophilus influenza type b, varicella (chicken pox), pneumococcal disease, meningococcal C, rotavirus, human papillomavirus (HPV) and influenza.

Deaths from vaccine-preventable diseases have fallen for the general population by 99% since the introduction of childhood vaccinations - it is estimated that vaccinations have saved around 78,000 lives between 1932 and 2003 (Burgess 2003). Internationally, vaccinations have been effective in reducing the disease disparities between Aboriginal and Torres Strait Islander and non-Indigenous populations, despite differences in the socioeconomic circumstances of these populations (Menzies & Singleton 2009).

Vaccinations are necessary not only in childhood: pregnant and post-partum women are subject to high risk from severe illness and complications from influenza, and maternal vaccination is shown to protect mothers and infants from illness (Overton 2016). Indigenous adults may be at increased risk of severe illness resulting from influenza and invasive pneumococcal disease due to other risk factors and comorbidities. Programs to make these vaccines accessible have led to improved vaccination rates.

Findings

What does the data tell us?

Children

According to the National Immunisation Program Schedule, Australian children are expected to have received specific immunisations by age 1, 2 and 5. As at December 2018, the vaccination coverage rate was similar between Indigenous and Other children:

• By age 1, the coverage rate was 92% for Indigenous children and 94% for Other children.
• By age 2, the coverage rate was 89% for Indigenous children and 91% for Other children.
• By age 5, the coverage rate was 97% for Indigenous children and 95% for Other children (Table D3.02.1).

The vaccination coverage rates for Indigenous children did not vary greatly by jurisdiction, particularly by age 5 (Table D3.02.2, Table D3.02.3, Table D3.02.4, Table D3.02-1). (Other children includes non-Indigenous children and those whose Indigenous status is unknown.)

Table 3.02-1: Vaccination coverage for children fully immunised at age 1 year, 2 years and 5 years, by Indigenous status and jurisdiction, 2018

Source: Tables D3.02.2, D3.02.3 & D3.02.4. AIHW analysis of data from the Australian Immunisation Register (AIR).

Between 2001 and 2018, there was a significant increase in the proportion of fully immunised Indigenous children aged 1 (from 82% to 92%). Over the same period, there was no change detected for children aged 2; however, this is affected by a recent increase in the number of vaccines scheduled for this age group (Table D3.02.5, Figure 3.02.1, Figure 3.02.2).

Between 2008 and 2018, there was also a significant increase in the proportion of fully immunised Indigenous children aged 5 (from 77% to 97%). Note that the age at which older children are assessed changed from 6 years to 5 years in 2007 and comparisons of trends over time are affected by the introduction of new vaccines on the schedule (Table D3.02.5, Figure 3.02.3).

Figure 3.02.1: Vaccination coverage for children fully immunised at age 1, by Indigenous status, Australia, 2001–2018

Source: Table D3.02.5. AIHW analysis of data from the Australian Immunisation Register (AIR).

Figure 3.02.2: Vaccination coverage for children fully immunised at age 2, by Indigenous status, Australia, 2001–2018

Source: Table 3.02.5. AIHW analysis of data from the Australian Immunisation Register (AIR).

Figure 3.02.3: Vaccination coverage for children fully immunised at age 5 and 6, by Indigenous status, Australia, 2002–2018

Source: Table 3.02.5. AIHW analysis of data from the Australian Immunisation Register (AIR).

Immunisation of adults

The rate of immunisation of adults was based on self-reported data from the National Aboriginal and Torres Strait Islanders Health Survey (Health Survey).

The target group for adult influenza vaccines for the general population is those aged 65 and over. Due to higher risks, Indigenous Australians are eligible for free vaccines at younger ages.

In 2018–19, it was estimated that more than two thirds (68%) of Indigenous Australians aged 50 and over had been vaccinated against influenza in the previous 12 months. Proportions were significantly higher for those living in Remote areas (73%) compared with Non-remote areas (67%) (Table D3.02.8, Figure 3.02.4).

Between 2012–13 and 2018–19, there was an increase in the rate of vaccination against influenza among Indigenous Australians aged 50 and over, from 57% to 68%. In Remote areas, the rate increased from 68% to 73% over the period, and in Non-remote areas, the increase was from 54% to 67% (Table 3.02.8).

Indigenous Australians aged 65 and over had higher rates of immunisation against influenza in the previous 12 months (84%) compared with those aged 50–64 (62%) (Table D3.02.7, Figure 3.02.4). 

For the general population, the 2009 Adult Vaccination Survey showed that 75% of those aged 65 and over had been immunised against influenza (AIHW 2011).

Figure 3.02.4: Indigenous Australians aged 50 and over who had immunisation against influenza in the last 12 months, by age and remoteness, 2018–19

Source: Table D3.02.7, Table D3.02.8. AIHW and ABS analysis of National Aboriginal and Torres Strait Islander Health Survey 2018–19.

In 2018–19, 32% of Indigenous Australians aged 50 and over had been vaccinated against invasive pneumococcal disease in the last five years. The vaccination rates for pneumonia for Indigenous Australians aged 50 and over was 34% in Remote areas and 32% in Non-remote areas. In 2012–13, these proportions were 35% in Remote areas and 27% in Non-remote areas (Table D3.02.8, Figure 3.05.5). 

In 2018–19, Indigenous Australians aged 65 and over had higher rates of immunisation against invasive pneumococcal disease in the last five years (46%) compared with those aged 50–64 (27%) (Table D3.02.7).

Vaccination against pneumococcal disease for all Australians aged 65 and over was 54% in 2009 (AIHW 2011).

Figure 3.02.5: Indigenous Australians aged 50 and over who had immunisation against invasive pneumococcal disease in the last 5 years, by age and remoteness, 2018–19

Source: Table D3.02.7, Table D3.02.8. AIHW and ABS analysis of National Aboriginal and Torres Strait Islander Health Survey 2018–19.

Adult vaccinations are also targeted at younger Indigenous Australians who have various risk factors, such as chronic medical conditions. In 2018–19, 40% of Indigenous Australians aged 15–49 were vaccinated for influenza in the previous year, and 7% had received a pneumococcal vaccination in the previous five years.

The 2018–19 Health Survey found that Indigenous Australians aged 15–49 who had diabetes/high blood sugar levels or circulatory diseases were significantly more likely to have had recent vaccinations for influenza (1.7 and 1.4 times, respectively) and pneumococcus (2.4 and 1.8 times, respectively) than Indigenous Australians without those diseases (Table D3.02.6).

What do research and evaluations tell us?

Recent research illustrates the importance of vaccinations for Indigenous Australians. The results point to the ongoing requirement for improvements in the rate of timely vaccinations for Indigenous children and the importance of vaccination in pregnancy and for older Indigenous Australians with increased risk of severe illness. Health care providers play a vital role in encouraging vaccinations for Indigenous Australian adults.

Hendry and others (2018) found that a program aimed at improving the rates of vaccinations contributed to the improved vaccination rates in Indigenous Australian children in New South Wales (Hendry et al. 2018). The cross-sectional study assessed both the vaccination rates and the timeliness of receipt of vaccinations in children. Vaccinations were compared across Indigenous and non-Indigenous children in New South Wales and the rest of Australia, between 2008 and 2016. A comparison of vaccination coverage before and after the introduction of the Aboriginal Immunisation Healthcare Worker (AIHCW) Program in New South Wales in 2012 showed a significant increase in rates of Indigenous and non-Indigenous children fully vaccinated at 9, 15 and 51 months of age. The increases in the vaccination rate were prominent in New South Wales after the introduction of the AIHCW Program compared with the rest of Australia.

Maternal immunisation has the potential to reduce the burden of infectious diseases in both pregnant women and infants. Marshall and others 2016 assessed maternal immunisation internationally and noted the role of cultural factors in vaccination programs in order to maximise the uptake of new vaccines for pregnant women (Marshall et al. 2016). They also emphasised the importance of pregnant women having confidence in immunisation providers.

Moberley and others 2016 recommend prioritising activities to improve and monitor maternal influenza vaccination coverage for Indigenous women (Moberley et al. 2016). Indigenous pregnant women who participated in a vaccination trial before and during the 2009 H1N1 influenza pandemic were studied to determine vaccination coverage. Key findings included:

• Vaccine coverage over the study period increased from 2.2% in the period 2006 to 2009 to 41% in the period 2009 to 2010.
• Increased maternal influenza vaccination coverage signified greater readiness of Indigenous women to be vaccinated.

In a survey of Indigenous Australian mothers who had recently given birth in Central Australia, Krishnaswamy and others (2018), found:

• Awareness and uptake by pregnant mothers of influenza vaccination was greater than for pertussis (whooping cough).
• Vaccination self-reporting underestimated vaccine coverage.
• There was a good understanding of public health messages of the benefits of maternal vaccination.
• Lack of health care provider recommendations is the main reason for non-vaccination (Krishnaswamy et al. 2018).

A study in New South Wales found barriers to influenza vaccination among Indigenous Australian adults included health system barriers and misconceptions among Indigenous Australians about the vaccine. Poor quality Indigenous status identification in primary health care settings and insufficient recommendations and reminders from health care providers may be contributing to a lack of awareness and lower uptake of the vaccine. There were also misconceptions among Indigenous Australians over vaccine effectiveness, safety and the severity of influenza. Younger adults and more highly educated adults were less likely to get vaccinated (Menzies et al. 2020).

Data from the national key performance indicators for Indigenous-specific primary health care show that influenza vaccination coverage for adults aged over 50 is improving and stronger improvements are being seen in major cities (albeit from a lower base) (AIHW 2020). This highlights the value of having good quality service-level data for driving improvements, and that Aboriginal Community Controlled Health Services are demonstrating to mainstream services that progress is possible even in difficult to reach non-remote environments. Further research is needed to unpack successful strategies to improve vaccination that can be implemented, in particular in mainstream primary health care.

High rates of the first dose of the human papillomavirus (HPV) vaccination among Indigenous Australian adolescents is being seen in school-based programs, but strategies are needed to improve the completion rates for Indigenous Australians (Brotherton et al. 2019).

Implications

Achieving good immunisation coverage reflects the strength and effectiveness of primary health care and demonstrates the benefits of large scale vaccination programs that have little or no cost to eligible participants. The high rates of vaccination for Indigenous Australian children is a significant achievement. However, there are still improvements that can be made to increase the vaccination rates in Indigenous Australian children, adolescents and adults. Targeted communication strategies to overcome barriers to vaccination and misconceptions about vaccination could be beneficial.

Health care providers play a central and vital role in encouraging vaccination. Research is needed into effective strategies for encouraging vaccination among Indigenous Australian clients of mainstream primary health care. There is also a need for better identification of Indigenous clients of mainstream primary health care in order for services to make vaccinations more available to Indigenous Australian adults. Data collection for continuous quality improvement can be used to drive or at least demonstrate improvements. The higher rates of Indigenous adult vaccination in Remote areas suggests that this is a strength of Indigenous-specific primary health care with potential lessons for mainstream care. However, improvements in both Remote and Non-remote areas are encouraging.

Trend data on vaccine-preventable hospitalisations is not available due to data coding changes in recent years. This would provide an indication as to the effect of recent increases in Indigenous adult vaccination for influenza and invasive pneumococcal disease.

The policy context is at Policies and strategies.

References

• AIHW (Australian Institute of Health and Welfare) 2011. 2009 Adult Vaccination Survey: summary results. Cat. no. PHE 135. Canberra: AIHW.
• AIHW 2020. Indigenous primary health care: results from the OSR and nKPI collections. Canberra: AIHW.
• Brotherton JM, Winch KL, Chappell G, Banks C, Meijer D, Ennis S et al. 2019. HPV vaccination coverage and course completion rates for Indigenous Australian adolescents, 2015. Medical Journal of Australia 211:31-6.
• Burgess M 2003. Immunisation: a public health success. New South Wales Public Health Bulletin 14:1‑5.
• Hendry AJ, Beard FH, Dey A, Meijer D, Campbell-Lloyd S, Clark KK et al. 2018. Closing the vaccination coverage gap in New South Wales: the Aboriginal Immunisation Healthcare Worker Program. The Medical Journal of Australia 209:24-8.
• Krishnaswamy S, Thalpawila S, Halliday M, Wallace EM, Buttery J & Giles M 2018. Uptake of maternal vaccinations by Indigenous women in Central Australia. Australian and New Zealand journal of public health 42:321.
• Marshall H, McMillan M, Andrews RM, Macartney K & Edwards K 2016. Vaccines in pregnancy: The dual benefit for pregnant women and infants. Hum Vaccin Immunother 12:848-56.
• Menzies R, Aqel J, Abdi I, Joseph T, Seale H & Nathan SA 2020. Why is influenza vaccine uptake so low among Aboriginal adults? Australian and New Zealand journal of public health 44:279-83.
• Menzies R & Singleton RJ 2009. Vaccine preventable diseases and vaccination policy for indigenous populations. Pediatric Clinics of North America 56:1263-83.
• Moberley SA, Lawrence J, Johnston V & Andrews RM 2016. Influenza vaccination coverage among pregnant Indigenous women in the Northern Territory of Australia. Commun Dis Intell Q Rep 40:E340‑E6.
• Overton K, Webby R, Markey P & Krause V 2016. Influenza and pertussis vaccination coverage in pregnant women in the Northern Territory in 2015 – new recommendations to be assessed. Vol. 23 (ed., Health Do). Centre for Disease Control, 1-8.