Australian Immunisation Register Research Articles

The effect of a financial incentive on COVID-19 vaccination uptake, and predictors of uptake, in people experiencing homelessness: A randomized controlled trial

People who are homeless are at increased risk of COVID-19 infection, and of poorer associated outcomes. Delivering vaccinations to, and ensuring uptake of multiple doses in, people who are homeless is complex. Financial incentives may improve vaccination uptake, particularly in people who have not received routine vaccinations previously, though evidence about the effect of incentives is limited and variable.This randomized controlled trial (ANZCTR 383156) assessed the effect of a financial incentive (an A$10 grocery voucher) on uptake of the second COVID-19 vaccination in Australian adults who were homeless, and who had received their first dose. Participants were recruited through a vaccination program for people experiencing homelessness between September 2021 and January 2022. They were followed-up for a minimum of 6.5 months. Uptake was measured ‘on-time’ at 6 weeks, and at any time during the trial period. Vaccination status was checked on the Australian Immunisation Register. Demographic and vaccination program characteristics associated with uptake were also investigated.Eighty-six people consented to participate, and 43 were randomly allocated to each of the ‘incentive’ and ‘no incentive’ groups. The incentive slightly increased the likelihood of a participant receiving a second vaccination on-time (risk difference (RD), 11.6 % [95 %CI, −9.0, 32.2 %]; p = 0.27), and at any time during the trial (RD, 14.0 % [95 %CI, –2.2, 30.1 %], p = 0.09). The incentive had a significant positive effect on uptake in people with no previous vaccination history, increasing their likelihood of receiving a second vaccination on-time (RD, 42.3 % [95 %CI, 15.7, 68.8 %]; p = 0.002) and at any time during the trial (RD, 38.7 % [95 %CI, 16.1, 61.3 %], p < 0.001).Financial incentives may increase COVID-19 vaccination uptake in people who are homeless, and particularly those who have no previous vaccination history. Future research should consider alternative incentive values, types, and cost-effectiveness.

Using the Australian Immunisation Register to support general practices to improve childhood vaccination rates.

Strategies to improve vaccination rates have been implemented with considerable benefits. The main objective of this study was to assess the impact of a supported general practice intervention to 'catch up' overdue children. Between 2017 and 2018, a public health nurse visited 23general practices with high numbers of overdue children to assist staff identify and follow up truly overdue children. A comparison group consisted of a random sample of overdue children from other practices. The intervention was assessed by reviewing Australian Immunisation Register (AIR) records in 2019. Although the intervention group had a significantly higherproportion of children who had their AIR records corrected for vaccines administered prior to the initial practice visit, the intervention did not result in higher vaccination rates. Support to general practices can improve vaccination data on the AIR; however, simple reminders alone are unlikely to increase vaccination rates for truly overduechildren.

Acute disseminated encephalomyelitis and transverse myelitis following COVID-19 vaccination – A self-controlled case series analysis

Acute Disseminated Encephalomyelitis (ADEM) and Transverse Myelitis (TM) are within the group of immune mediated disorders of acquired demyelinating syndromes. Both have been described in temporal association following various vaccinations in case reports and case series and have been evaluated in observational studies. A recent analysis conducted by The Global Vaccine Data Network (GVDN) observed an excess of ADEM and TM cases following the adenoviral vectored ChAdOx1 nCoV-19 (AZD1222) and mRNA-1273 vaccines, compared with historically expected background rates from prior to the pandemic. Further epidemiologic studies were recommended to explore these potential associations.We utilized an Australian vaccine datalink, Vaccine Safety Health-Link (VSHL), to perform a self-controlled case series analysis for this purpose. VSHL was selected for this analysis as while VSHL data are utilised for GVDN association studies, they were not included in the GVDN observed expected analyses. The VSHL dataset contains vaccination records sourced from the Australian Immunisation Register, and hospital admission records from the Victorian Admitted Episodes Dataset for 6.7 million people. These datasets were used to determine the relative incidence (RI) of G040 (ADEM) and G373 (TM) ICD-10-AM coded admissions in the 42-day risk window following COVID-19 vaccinations as compared to control periods either side of the risk window.We observed associations between ChAdOx1 adenovirus vector COVID-19 vaccination and ADEM (all dose RI: 3.74 [95 %CI 1.02,13.70]) and TM (dose 1 RI: 2.49 [95 %CI: 1.07,5.79]) incident admissions. No associations were observed between mRNA COVID-19 vaccines and ADEM or TM. These findings translate to an extremely small absolute risk of ADEM (0.78 per million doses) and TM (1.82 per million doses) following vaccination; any potential risk of ADEM or TM should be weighed against the well-established protective benefits of vaccination against COVID-19 disease and its complications.This study demonstrates the value of the GVDN collaboration leveraging large population sizes to examine important vaccine safety questions regarding rare outcomes, as well as the value of linked population level datasets, such as VSHL, to rapidly explore associations that are identified.

The impact of changes in opioid dependency treatment upon COVID-19 transmission in Sydney, Australia: a retrospective longitudinal observational study

BackgroundIn April 2020, in response to the COVID-19 public health emergency, South Eastern Sydney Local Health District (SESLHD) Drug and Alcohol services modified their delivery of opioid dependency treatment (ODT) to reduce spread of COVID-19 and maintain continuity of care by increasing use of takeaway doses (TADs), transferring clients to local community pharmacies for dosing and encouraging the use of long-acting depot buprenorphine (LADB) which enabled once a month dosing.MethodsThis study was a retrospective longitudinal case–control study conducted from August 1st, to November 30th, 2021. Eligible clients were those admitted for treatment with SESLHD ODT Services prior to August 1st,2021 and who remained in treatment beyond November 30th, 2021. COVID-19 diagnoses were determined by a COVID-19 PCR and extracted from the electronic Medical Records (eMR) Discern Reporting Portal. Demographic, clinical and dosing related data were collected from eMR and the Australian Immunisation Register (AIR).ResultsClients attending SESLHD ODT services had significantly greater odds of acquiring COVID-19 than the NSW adult population at large (OR: 13.63, 95%CI: 9.64,18.88). Additionally, amongst SESLHD ODT clients, being of Aboriginal and Torres Strait Islander origin was associated with greater odds of acquiring COVID-19 (OR = 2.18, CI: 1.05,4.53); whilst being employed (OR = 0.06, CI:0.01,0.46), receiving doses at pharmacy (OR = 0.43, CI: 0.21,0.89), and being vaccinated (OR = 0.12, CI: 0.06,0.26) were associated with lower odds. Every additional day of attendance required for dosing was associated with a 5% increase in odds of acquiring COVID-19 (OR = 1.05, CI: 1.02,1.08).ConclusionsClients attending SESLHD ODT services are significantly more likely to acquire COVID-19 than the NSW population at large. Promoting vaccination uptake, transferring clients to pharmacy, and reducing the frequency of dosing (by use of takeaway doses or long-acting depot buprenorphine) are all potential methods to reduce this risk.

Emergency department presentations for chest complaints after mRNA COVID-19 vaccinations in children and adolescents.

To investigate characteristics and management of children presenting with chest complaints to a tertiary paediatric ED post-mRNA COVID-19 vaccine. This was a retrospective medical record review with data linkage to the Australian Immunisation Register. The study setting was the Royal Children's Hospital, Melbourne, Australia. Children <18 years who had a troponin blood test performed in hospital within 14 days of receiving mRNA COVID-19 vaccination were included. Elevated troponin and myocarditis or pericarditis as per Brighton criteria was the primary outcome. Vaccination status, length of stay, investigations and clinical management were secondary outcomes. Six hundred and ten patients had a troponin test in 13 months. After exclusion of trauma-related tests (n = 31), known cardiac patients (n = 75) and others (n = 145), 359 troponins were obtained due to chest complaints and related symptoms, with 283 troponins assessed to be mRNA vaccination-related. There was a temporal peak in presentations with a 30-fold monthly increase in troponin post-commencement of mRNA COVID-19 vaccines. In those with chest complaints following mRNA vaccination, mean age was 14 years and 50.4% were female. Fourteen out of 283 (5%) vaccine-related troponins were abnormal with 14 patients assessed to have vaccine-associated myocarditis. No patients had pericarditis. There was a large number of possible mRNA COVID-19 vaccine-related chest complaints presenting to the ED. Few patients had abnormal troponins or myocarditis.

Effectiveness of COVID-19 vaccination against COVID-19 specific and all-cause mortality in older Australians: a population based study

Few studies have examined effectiveness of COVID-19 vaccines against COVID-19 and all-cause mortality across different pandemic periods in2022. We used linked whole-of-population data from the 2021 Australian Census, Australian Immunisation Register, death registrations and other national datasets including migration data. Among 3.8 million adults aged 65+ years and >170,000 aged care residents, we used survival analysis to estimate vaccine effectiveness (VE) against COVID-19 specific mortality and all-cause mortality, by vaccine dose and time since receipt, adjusted for age, sex and other factors. We also estimated absolute COVID-19 mortality rates. From January-May 2022 (Omicron BA.1/2), 3250 COVID-19 deaths occurred; from June-November (Omicron BA.4/5) 3185 COVID-19 deaths occurred. During January-May, VE of a 3rd COVID-19 vaccine dose within 3 months was 93% (95% CI 93-94%) whilst VE of a 2nd dose >6 months since receipt was 34% (26-42%). During June-November, VE of a 4th COVID-19 vaccine dose within 3 months was 84% (82-86%) whilst VE of a 3rd dose >6 months since receipt was 56% (50-62%). VE estimates for aged care residents were similar, but absolute risk reductions were substantially greater. During June-November 2022, for all-cause mortality, VE of a 4th dose within 3 months was 58% (56-59%) whilst VE of a 3rd dose >6 months since receipt was 19% (16-22%). COVID-19 vaccination is highly effective against COVID-19 mortality among older adults although effectiveness wanes with time since the last dose. Our findings emphasise the importance of continuing to administer booster doses, particularly to those at highest risk. This study was funded by the Health Economics Research Division in the Australian Government Department of Health and Aged Care.

Live vaccines following intravenous immunoglobulin for Kawasaki disease: Are we vaccinating appropriately?

Australian and New Zealand guidelines recommend that live vaccines be postponed for 11 months after treatment of Kawasaki disease (KD) with intravenous immunoglobulin (IVIG). We aimed to describe patterns of live-vaccine administration after KD treatment, focusing on the measles-mumps-rubella/measles-mumps-rubella-varicella (MMR/MMRV) vaccines, and to compare real-world practice with current recommendations. We combined data from inpatient Electronic Health Records and the Australian Immunisation Register for all children who received IVIG for the treatment of KD under the age of 5 years at two Australian tertiary children's hospitals over a 12-year period. Children who received IVIG <11 months before a scheduled MMR/MMRV were deemed 'at risk' of breaching the guidelines, and those whose subsequent vaccination occurred <11 months after the IVIG were deemed to have 'breached' the guidelines. Of those at risk, three-quarters (76%) breached the guidelines for their first MMR/MMRV. Findings were similar (50%-80%) for the second MMR/MMRV dose. The majority of Australian children treated for KD with IVIG may not be optimally protected by MMRV vaccination. Immunisation systems should address this avoidable risk.

Self-reported HPV vaccination and vaccination record linkage in the Australian Oral Diversity Study.

Australia has a school-based human papillomavirus (HPV) vaccination scheme that was implemented for girls in 2007 and for boys in 2013. HPV vaccination status is important for many studies into HPV infection. Here we wanted to estimate the validity of self-reported HPV vaccination status by comparing self-report to data from the national vaccination register. Australian residents aged 18-70years were recruited for the Oral Diversity Study from October 2020 to November 2021. Participants were asked to provide consent for record linkage to the Australian Immunisation Register (AIR). They were also asked to fill out a questionnaire about HPV vaccination, lifestyle, and sexual behavior. 1,023 participants were recruited, permission was received from 911 participants for HPV vaccination record linkage, and 850 self-reported vaccination and were part of the validity analysis. Of those 233 (26%) were confirmed to be HPV vaccinated. Ninety-one percent of the vaccinated were females (n = 212), 19 males and two non-binary. The highest HPV vaccine uptake was seen in the youngest age group (18-29years; 80%), followed by 66% in 30-39year olds, 2% in 40-49year olds and then dropped significantly to 0.7% for people 50-70years old. The sensitivity of self-report was 99.0%, and the specificity 94.5%, and the positive predictive value was 85.7% and the negative predictive value 99.7%. We found that the correlation between self-reported Gardasil® vaccination and the AIR records were very good, with high sensitivity and specificity.

Annual immunisation coverage report 2021.

We analysed Australian Immunisation Register (AIR) data as at 3 April 2022 for children, adolescents and adults for the calendar year 2021, with data on trends from previous years also presented. 'Fully vaccinated' coverage in Australian children in 2021 was 0.6-0.8 of a percentage point lower than in 2020 at the 12-month (94.2%) and 60-month (94.0%) age assessment milestones, but stable at the 24-month milestone (92.1%). Due to the lag time involved in assessment at milestone ages, 'fully vaccinated' coverage figures for 2020 and 2021 predominantly reflect vaccinations due in 2019 and 2020, respectively, and hence show a small impact on childhood coverage in the first year of the coronavirus disease 2019 (COVID-19) pandemic. 'Fully vaccinated' coverage in Aboriginal and Torres Strait Islander (hereafter respectfully referred to as Indigenous) children was 0.7-1.5 percentage points lower in 2021 than 2020 at the 12-month (91.6%), 24-month (90.1%) and 60-month (96.3%) milestones, although 2.3 percentage points higher than children overall at 60 months. Influenza vaccination coverage in children aged 6-59 months was approximately 20 percentage points lower in 2021 than 2020, both for children overall (26.5%) and for Indigenous children (22.5%). 'On time' vaccination (within 30 days of the recommended age) was up to two percentage points lower in 2021 than 2020 for vaccines due at 4 and 6 months of age, suggesting possible pandemic impacts, but was similar or higher for vaccines due at 12 months of age. While on-time vaccination in Indigenous children has improved progressively since 2012, it remained 6-13 percentage points lower than in children overall in 2021. 'Fully vaccinated' coverage at the earlier milestones (3 months after due date of last scheduled vaccine) of 9, 15, 21 and 51 months was 1.5-2.8 percentage points lower for children living in the least advantaged residential area quintile than the most advantaged, a similar disparity as in 2020. Coverage at the earlier milestones was 2.3-10.0 percentage points lower for Indigenous children living in remote areas than in major cities and regional areas, with disparity at 21 months of age 2.1-2.2 percentage points higher in 2021 than in 2020, and 1.2-2.1 percentage points higher at 51 months. In 2021, a total of 80.3% of girls and 77.2% of boys (and 73.3% and 66.2% of Indigenous girls and boys) had completed the human papillomavirus (HPV) vaccination schedule by 15 years of age, 0.2-0.4 of a percentage point lower than 2020 (1.7-1.8 percentage points for Indigenous), reflecting vaccinations due in school programs prior to the pandemic with possible pandemic impact on catch-up vaccination. However, the proportion of adolescents completing the two-dose HPV vaccination schedule within a calendar year was 15.3 percentage points lower in 2021 than 2020 and 26.9 percentage points lower than in 2019, likely due to pandemic-related disruption to school-based programs. Additionally, 87.3% of adolescents (83.8% for Indigenous) had received the recommended booster dose of diphtheria-tetanus-acellular pertussis (dTpa) vaccine by 15 years, and 76.1% (66.7% for Indigenous) the recommended meningococcal ACWY vaccine dose by 17 years of age. Zoster vaccine coverage in 2021 remained relatively low, at just over 30%, in adults aged 70 years, but increased to 47% in those aged 71-79 years, reflecting ongoing catch-up vaccination. Coverage of 13vPCV was low in 2021, reaching 17.2% in adults aged 70 years and 20.1% in those aged 71-79 years. Influenza vaccination coverage in adults in 2021 was progressively higher with increasing age, reaching 62.1% in the 65-74 years age group (64.6% in Indigenous) and 68.5% in the 75+ years age group (67.7% in Indigenous). Influenza vaccine coverage for other National Immunisation Program (NIP)-eligible Indigenous adult age groups was only 22.0% for those aged 20-49 years, and 43.5% for those aged 50-64 years. By the end of 2021, a total of 91.6% of people in Australia aged 16+ years had received a second dose of a COVID-19 vaccine (71.8% for Indigenous), with over 99% of those aged 70+ years having received a second dose. Vaccination coverage in children and adolescents remained relatively high in 2021, although with some evidence of COVID-19 pandemic impacts, particularly on receipt of two doses of HPV vaccine within the same calendar year. It will be important to ensure catch-up vaccination in children and adolescents occurs. A strengthened focus on adult vaccination is needed, as coverage remained suboptimal in 2021. The impact of mandatory reporting of all NIP vaccinations from mid-2021, on completeness of AIR data, has not yet been formally evaluated.

Randomised controlled trials of behavioural nudges delivered through text messages to increase influenza and COVID-19 vaccines among pregnant women (the EPIC study): study protocol

BackgroundInfluenza and COVID-19 infections during pregnancy may have serious adverse consequences for women as well as their infants. However, uptake of influenza and COVID-19 vaccines during pregnancy remains suboptimal. This study aims to assess the effectiveness of a multi-component nudge intervention to improve influenza and COVID-19 vaccine uptake among pregnant women.MethodsPregnant women who receive antenatal care at five tertiary hospitals in South Australia, Western Australia and Victoria will be recruited to two separate randomised controlled trials (RCTs). Women will be eligible for the COVID-19 RCT is they have received two or less doses of a COVID-19 vaccine. Women will be eligible for the influenza RCT if they have not received the 2023 seasonal influenza vaccine. Vaccination status at all stages of the trial will be confirmed by the Australian Immunisation Register (AIR). Participants will be randomised (1:1) to standard care or intervention group (n = 1038 for each RCT). The nudge intervention in each RCT will comprise three SMS text message reminders with links to short educational videos from obstetricians, pregnant women and midwives and vaccine safety information. The primary outcome is at least one dose of a COVID-19 or influenza vaccine during pregnancy, as applicable. Logistic regression will compare the proportion vaccinated between groups. The effect of treatment will be described using odds ratio with a 95% CI.DiscussionBehavioural nudges that facilitate individual choices within a complex context have been successfully used in other disciplines to stir preferred behaviour towards better health choices. If our text-based nudges prove to be successful in improving influenza and COVID-19 vaccine uptake among pregnant women, they can easily be implemented at a national level.Trial registrationClinicalTrials.gov Identifier NCT05613751. Registered on November 14, 2022.

The effectiveness of vaccination for preventing hospitalisation with COVID-19 in regional Queensland: a data linkage study.

To estimate the effectiveness of vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for protecting people in a largely coronavirus disease 2019 (COVID-19)-naïve regional population from hospitalisation with symptomatic COVID-19. Retrospective cohort study; analysis of positive SARS-CoV-2 polymerase chain reaction (PCR) test results linked with Central Queensland hospitals admissions data and Australian Immunisation Register data. Adult residents of Central Queensland, 1 January - 31 March 2022. Vaccine effectiveness (1 - relative risk of hospitalisation for vaccinated and unvaccinated people) with respect to protecting against hospitalisation with symptomatic COVID-19 after primary vaccination course only (two doses of an approved SARS-CoV-2 vaccine) and after a booster vaccine dose. Positive SARS-CoV-2 test results were recorded during 1 January - 31 March 2022 for 9682 adults, 7244 of whom had been vaccinated (75%); 5929 people were aged 40 years or younger (62%), 5180 were women (52%). Forty-seven people were admitted to hospital with COVID-19 (0.48%), four required intensive care (0.04%); there were no in-hospital deaths. Vaccine effectiveness was 69.9% (95% confidence interval [CI], 44.3-83.8%) for people who had received only a primary vaccination course and 81.8% (95% CI, 39.5-94.5%) for people who had also received a booster. Of the 665 Aboriginal and Torres Strait Islander adults with positive SARS-CoV-2 test results, 401 had been vaccinated (60%). Six Indigenous people were hospitalised with symptomatic COVID-19 (0.9%); vaccine effectiveness was 69.4% (95% CI, -56.5% to 95.8%) for Indigenous people who had received a primary vaccination course only or the primary course and a booster. The hospitalisation rate for Central Queensland people with PCR-confirmed Omicron variant SARS-CoV-2 infections during the first quarter of 2022 was low, indicating the protection afforded by vaccination and the value of booster vaccine doses.

Vaccine intention and hesitancy among Australian women who are currently pregnant or have recently given birth: the Birth in the Time of COVID-19 (BITTOC) national online survey

ObjectiveTo examine the prevalence of COVID-19 vaccination, and factors associated with vaccination intention and hesitancy in pregnant and postnatal women in Australia.Design and settingA national online survey was conducted over...

Oral human papillomavirus (HPV) infection and HPV vaccination in an Australian cohort.

Human papillomavirus (HPV)-related oropharyngeal cancer (OPC) is increasing in incidence, yet very little is known about oral HPV infection in the general population. In this Australian-based study we assess oral HPV prevalence according to HPV vaccination status. Participants of the Oral Diversity Study were Australian residents, aged 18 to 70 years, who filled out a questionnaire about lifestyle and sexual behaviour, and donated a saliva sample in 2020 to 2021. We obtained permission to access HPV vaccination status through record linkage with the Australian Immunisation Register. Saliva samples were DNA extracted, DNA quality checked and analysed for HPV. We recruited 1023 participants to the Oral Diversity Study. Nine hundred twenty-one returned a saliva sample for analysis, 911 passed the DNA quality check and were included in the study. The oral HPV prevalence was 7.2%, and was strongly associated with sexual behaviours. We identified 27 different HPV types; 53% of participants carried high-risk HPV types, with no difference between the vaccinated and the unvaccinated groups (53% both, P = .979). Two hundred thirty participants (26%) were HPV vaccinated. The oral prevalence of the nine HPV types included in the nonavalent HPV vaccine was significantly lower in the vaccinated participants compared to the unvaccinated (0.9% vs 3.4%; P = .022). These findings suggest that a sizeable minority of Australian residents harbour oral HPV infections, and many of these are high-risk subtypes. We found some evidence that HPV vaccination resulted in lower prevalence of oral HPV infections of vaccine-specific types. Larger surveys are required to confirm these findings.

Safety of mRNA vaccination for COVID‐19 in children with polyethylene glycol (PEG)‐asparaginase allergy

Safety of <scp>mRNA</scp> vaccination for <scp>COVID</scp>‐19 in children with polyethylene glycol (<scp>PEG</scp>)‐asparaginase allergy

Using data linkage to monitor COVID-19 vaccination: development of a vaccination linked data repository.

The COVID-19 Vaccination Linked Data Repository (CVLDR) was established in 2021 to assist with the implementation and management of the COVID-19 vaccination program in the State of Western Australia (WA). The CVLDR contains a number of datasets including the Australian Immunisation Register, hospital admissions, emergency department attendances, notifiable infectious disease, and laboratory data. Datasets in the CVLDR are linked using a probabilistic method at the WA Department of Health. Quality assurance mechanisms have been established to identify and mitigate potential errors in the linkage. Each of the datasets has varying degrees of data quality and completeness, however most are of high standard, underpinned by legislation. The linking of the datasets within the CVLDR has allowed for increased public health utility in the immunisation program including the areas of vaccine safety, effectiveness, and coverage.

Real world impact of 13vPCV in preventing invasive pneumococcal pneumonia in Australian children: A national study

BackgroundWe aimed to assess the direct protective effect of 13 valent pneumococcal conjugate vaccine (13vPCV) against invasive pneumococcal pneumonia (IPP; including pneumonia and empyema) in children using a nation-wide case-control study across 11 paediatric tertiary hospitals in Australia. MethodsChildren < 18 years old admitted with pneumonia were eligible for enrolment. IPP was defined as Streptococcus pneumoniae (SP) cultured or detected by polymerase chain reaction (PCR) from blood or pleural fluid. Causative SP serotype (ST) was determined from blood or pleural fluid SP isolates by molecular methods in PCR positive specimens or else inferred from nasopharyngeal isolates. For each IPP case, 20 population controls matched by age and socio-economic status were sampled from the Australian Immunisation Register. Conditional logistic regression was used to estimate the adjusted odds ratio (aOR) of being fully vaccinated with 13vPCV (≥3 doses versus < 3 doses) among IPP cases compared to controls, adjusted for sex and Indigenous status. ResultsFrom February 2015 to September 2018, we enrolled 1,168 children with pneumonia; 779 were 13vPCV-eligible and were individually matched to 15,580 controls. SP was confirmed in 195 IPP cases, 181 of whom had empyema. ST3 and ST19A were identified in 52% (102/195) and 11% (21/195) of IPP cases respectively. The aOR of being fully vaccinated with 13vPCV was 0.8 (95% CI 0.6–1.0) among IPP cases compared to matched controls. ConclusionWe failed to identify a strong direct protective effect of 13vPCV against IPP among Australian children, where disease was largely driven by ST3.

Annual immunisation coverage report 2020.

We analysed Australian Immunisation Register (AIR) data as at 31 March 2021 for children, adolescents and adults. This is the first time that adolescent and adult coverage data from the AIR have been included in our annual coverage report.

HPV vaccination coverage: slightly improved two‐dose schedule completion estimates and historical estimates lower on AIR than HPV Register

ObjectiveTo compare Australian Immunisation Register (AIR) human papillomavirus (HPV) vaccination coverage against historical data from the former National HPV Vaccination Program Register and estimate two‐dose vaccination coverage. MethodsCross‐sectional analysis of registry data for adolescent birth cohorts (1998‐2007). Denominator populations were Medicare enrolments (AIR) and ABS estimated resident populations (HPV register). ResultsFor adolescents aged <17 years, AIR coverage estimates were several percentage points lower than HPV register estimates due to a larger Medicare enrolment denominator. Completed course coverage (two or three valid doses) for 15‐year‐old females in 2020 was 81.5% and for males 78.6%, higher than completed course coverage in 15‐year‐olds in 2019 (79.7 and 76.8% respectively). First dose coverage was similar for Indigenous adolescents but course completion was lower, although improving over time. Course completion was slightly lower (3.5‐5.7%) in areas of lowest socioeconomic status and greatest remoteness. ConclusionsCoverage is slightly lower using AIR than HPV register estimates. Moving from three to two doses has slightly improved completion, likely due to the wider dose spacing, but equity gaps remain. Implications for public healthAn ongoing focus on equity in vaccine delivery is needed. Systems, reminders and catch‐up opportunities to ensure course completion remain important.

How accurately does the Australian Immunisation Register identify children overdue for vaccine doses? A national cross-sectional study

The accuracy of data recorded in the Australian Immunisation Register (AIR) is important for assessment of population-level vaccine coverage but has not been assessed nationally since 2001. We undertook a cross-sectional study in five states in 2017 using standard criteria to validate AIR records classified as three months overdue for any vaccine at 12, 24 and 48 months. Of 2,000 records selected for audit, 905 were assessable, of which 124 (14%) were misclassified as overdue (errors). Among 563 general practice (GP) records, 91 (16.1%) were errors. Compared with Victoria (1/99; 1%), errors were significantly higher in Western Australia (11/106; 10.4%), Queensland (13/104; 12.5%), South Australia (23/110; 20.9%) and New South Wales (43/144; 29.9%); p &lt; 0.01 for all. Among 165 council and community health centre providers, the overall error rate (17; 10.3%) was non-significantly lower than for GP providers, with an odds ratio (OR) of 0.6 and a 95% confidence interval (95% CI) of 0.3–1.1, and did not differ between states. Records were transmitted to the AIR by paper-based methods in 13 cases, with significantly higher error rates (7/13; 54%) than for practice management software (77/630; 12.2%); OR 9.8 (95% CI 2.8–36.4) or the AIR secure site (23/87; 26.4%); OR 2.6 (95% CI 1.4–4.5). Accuracy is increasingly important, with mandatory reporting to the AIR for all National Immunisation Program vaccines from July 2021, and best achieved by uniform use of practice management software.

SMS reminders to improve the uptake and timeliness of the primary immunisation series in infants: a multi-centre randomised controlled trial.

Immunisation timeliness continues to present challenges to achieving optimal vaccine coverage in infancy, particularly in disadvantaged groups and Australian First Nations infants. We aimed to determine whether a tailored, educational SMS reminder improves the timeliness of immunisation in infants up to seven months of age. A pragmatic, three-arm, parallel-group, randomised controlled trial of immunisation reminders was conducted in two First-Nations-specific primary health care centres and two public hospital antenatal clinics in South East Queensland, Australia. Live-born infants of mothers enrolled during pregnancy were randomised at birth and followed to eight months of age. One group received a simple SMS reminder at two weeks before, the week of, and two weeks after the due date for immunisation at two, four and six months of age. The second group received a tailored SMS with an educational message at two weeks before and on the date immunisations were due; those not immunised two weeks following the due date were offered support to immunise the baby. Controls received no intervention or contact until the baby turned seven months of age. The primary outcome was the proportion of infants age-appropriately vaccinated at seven months of age as recorded on the Australian Immunisation Register. Secondary outcomes included vaccination status at three and five months of age. Between 30 May 2016 and 24 May 2018, one hundred and ninety-six infants (31% First Nations infants) were randomised. At seven months of age, 54/65 (83.1%) infants in the educational SMS ± additional support group (ESMS±S) were age-appropriately immunised, compared to 45/64 (70.3%) in the simple SMS group and 45/67 (67.2%) in controls. Differences were most marked at five months of age: ESMS±S 95.5%; simple SMS 73.4%; controls 75.8%. The difference between the ESMS±S group and the other two groups at seven months of age was no longer apparent when those who received additional support beyond the SMS were assumed to have not been vaccinated if that support had not been received. A tailored SMS reminder system using an educational message and with provision of additional support to mothers is more effective in improving immunisation timeliness in infants at three and five months of age than a simple message and no intervention. The additional support was required at seven months of age in order to achieve higher coverage in the ESMS±S group.