Comprehensive observational study evaluating the enduring effectiveness of 4CMenB, the meningococcal B vaccine against gonococcal infections in the Northern Territory and South Australia, Australia: study protocol.

INTRODUCTION: The effectiveness of antibiotics for treating gonococcal infections is compromised due to escalating antibiotic resistance; and the development of an effective gonococcal vaccine has been challenging. Emerging evidence suggests that the licensed meningococcal B (MenB) vaccine, 4CMenB is effective against gonococcal infections due to cross-reacting antibodies and 95% genetic homology between the two bacteria, Neisseria meningitidis and Neisseria gonorrhoeae, that cause the diseases. This project aims to undertake epidemiological and genomic surveillance to evaluate the long-term protection of the 4CMenB vaccine against gonococcal infections in the Northern Territory (NT) and South Australia (SA), and to determine the potential benefit of a booster vaccine doses to provide longer-term protection against gonococcal infections. METHODS AND ANALYSES: This observational study will provide long-term evaluation results of the effectiveness of the 4CMenB vaccine against gonococcal infections at 4-7 years post 4CMenB programme implementation. Routine notifiable disease notifications will be the basis for assessing the impact of the vaccine on gonococcal infections. Pathology laboratories will provide data on the number and percentage of N. gonorrhoeae positive tests relative to all tests administered and will coordinate molecular sequencing for isolates. Genome sequencing results will be provided by SA Pathology and Territory Pathology/New South Wales Health Pathology, and linked with notification data by SA Health and NT Health. There are limitations in observational studies including the potential for confounding. Confounders will be analysed separately for each outcome/comparison. ETHICS AND DISSEMINATION: The protocol and all study documents have been reviewed and approved by the SA Department for Health and Well-being Human Research Ethics Committee (HREC/2022/HRE00308), and the evaluation will commence in the NT on receipt of approval from the NT Health and Menzies School of Health Research Human Research Ethics Committee. Results will be published in peer-reviewed journals and presented at scientific meetings and public forums.

An Observational Study to Assess the Effectiveness of 4CMenB against Meningococcal Disease and Carriage and Gonorrhea in Adolescents in the Northern Territory, Australia-Study Protocol.

Invasive meningococcal disease (IMD) causes significant morbidity and mortality worldwide with serogroup B being the predominant serogroup in Australia and other countries for the past few decades. The licensed 4CMenB vaccine is effective in preventing meningococcal B disease. Emerging evidence suggests that although 4CMenB impact on carriage is limited, it may be effective against gonorrhoea due to genetic similarities between Neisseria meningitidis and Neisseria gonorrhoeae. This study protocol describes an observational study that will assess the effect of the 4CMenB vaccine against meningococcal carriage, IMD and gonorrhoea among adolescents in the Northern Territory (NT). All 14-19-year-olds residing in the NT with no contraindication for 4CMenB vaccine will be eligible to participate in this cohort study. Following consent, two doses of 4CMenB vaccine will be administered two months apart. An oropharyngeal swab will be collected at baseline and 12 months to detect pharyngeal carriage of Neisseria meningitidis by PCR. The main methodological approaches to assess the effect of 4CMenB involve a nested case control analysis and screening method to assess vaccine effectiveness and an Interrupted Time Series regression analysis to assess vaccine impact. Research ethics approvals have been obtained from Menzies and Central Australian Human Research Ethics Committees and the Western Australian Aboriginal Health Ethics Committee. Results will be provided in culturally appropriate formats for NT remote and regional communities and published in international peer reviewed journals. ClinicalTrials.gov Identifier: NCT04398849.

Acute lower respiratory infections in Indigenous infants in Australia's Northern Territory across three eras of pneumococcal conjugate vaccine use (2006-15): a population-based cohort study.

BACKGROUND: The burden of acute lower respiratory infection (ALRI) in Indigenous children of Australia's Northern Territory is among the highest globally. No published data exists on the effect of pneumococcal conjugate vaccine (PCV) introduction on ALRIs in this population beyond 2005. The aim of this study was to describe the rates of ALRI admissions to hospital in Indigenous infants in the Northern Territory from 2006 to 2015, across three periods of different PCV use. We hypothesised that broader valency PCVs would be more effective against hospitalisations for pneumonia. METHODS: We did a retrospective population-based cohort study of Indigenous infants born in the Northern Territory followed up until age 12 months. Data were from administrative hospital and perinatal datasets. International classification of diseases codes (tenth revision, Australian modification; ICD-10AM) were used to identify respiratory hospitalisations of interest: all-cause ALRI, all-cause pneumonia, bacterial pneumonia, viral pneumonia, influenza-like illness (ILI), respiratory syncytial virus ALRI (RSV-ALRI), and pneumococcal ALRI. Incidence rates were compared between PCV eras (7-valent PCV [PCV7], 2006-09; 10-valent PCV [PCV10], 2009-11; and 13-valent PCV [PCV13], 2011-15) using interrupted time trend analysis and negative binomial regression. FINDINGS: For children born between Jan 1, 2006, and Dec 31, 2015, 4138 ALRI episodes (31% of all hospitalisations) occurred among 2888 (20%) of the 14 594 infants. The overall ALRI hospitalisation rate was 29·7 episodes per 100 child-years. Prominent risk factors associated with ALRI hospitalisation were living in a remote community or the Central desert region, being born preterm or with low birthweight. ALRI rates were lowest in the PCV13 era, in association with a significant reduction in bacterial pneumonia hospitalisations in the PCV13 era compared with the PCV10 (incidence rate ratio 0·68, 95% CI 0·57-0·81) and PCV7 (0·70, 0·60-0·81) eras. In contrast, RSV-ALRI rates were 4·9 episodes per 100 child-years in each era. INTERPRETATION: A 30% reduction in bacterial-coded pneumonia hospitalisations in the Northern Territory during the era of PCV13 immunisation supports its ongoing use in the region. Despite the reduction, one in five Indigenous infants born in the region continue to be hospitalised with an ALRI in their first year of life. Future gains require multifaceted environmental and biomedical approaches. FUNDING: National Health and Medical Research Council of Australia.

Gaps in maternal influenza vaccine uptake in Northern Territory: A need for a year-round influenza vaccination campaign.

INTRODUCTION: Maternal influenza vaccination was introduced in 2010 due to the high morbidity and mortality associated with influenza in pregnancy. The aim of this study was to assess the maternal influenza vaccination uptake in Northern Territory public hospitals and identify gaps to improve uptake. METHODS: Birth data from Northern Territory (NT) public hospitals obtained from the Perinatal Register for deliveries in 2016 were merged with vaccination records from the NT immunisation register. RESULTS: There were 3,392 viable pregnancies in NT public hospitals in 2016 with 45.6% vaccination coverage against influenza. There was a statistically significant difference in coverage with 68.5% in Indigenous vs 31.7% in non-Indigenous deliveries (p < 0.001), yielding an odds ratio of 4.67 (95% CI 4.02, 5.42) for maternal influenza vaccination across Indigenous status. Influenza vaccination coverage for preterm births (< 37 weeks) was low especially in non-Indigenous mothers at 27.2% vs 65.05% in Indigenous mothers (p < 0.001). A distinct immunisation administration pattern was noted for 2016 with 58.9% of vaccinations occurring between April and June regardless of Indigenous status and maternal gestational age. This correlated with the annual influenza immunisation campaign by the NT and Commonwealth. CONCLUSION: A year-round maternal influenza vaccination campaign is crucial to avoid missed opportunities and increase vaccination protection for mother and baby. Antenatal influenza vaccination campaign with health care workers education and increasing patient awareness should continue throughout the year.

HPV vaccination coverage and course completion rates for Indigenous Australian adolescents, 2015.

OBJECTIVE: To estimate human papillomavirus (HPV) vaccination coverage and course completion rates for Indigenous adolescents in four Australian states and territories. PARTICIPANTS, SETTING: Adolescents who were 12 years old in 2015 and received the quadrivalent HPV vaccine (three doses: 0, 2, 6 months) as part of the National HPV Vaccination Program in 2015 or 2016 in New South Wales, Queensland, the Northern Territory, or the Australian Capital Territory. MAIN OUTCOME MEASURES: Estimated HPV vaccination coverage by dose and by Indigenous status and sex, based on National HPV Vaccination Program Register data; vaccination course completion rates (proportion of dose 1 recipients who received dose 3) for 12-year-olds vaccinated during 2013-2016, by sex, jurisdiction, and Indigenous status. RESULTS: Dose 1 coverage exceeded 80% for all Indigenous status/jurisdiction/sex groups (range, 83.3-97.7%). Coverage was similar for Indigenous and non-Indigenous girls in Queensland (87.3% v 87.0%), lower for Indigenous girls in the ACT (88.7% v 97.7%) and the NT (91.1% v 97.0%), and higher in NSW (95.9% v 89.9%); it was similar for Indigenous and non-Indigenous boys in all jurisdictions except the NT (88.6% v 96.3%). Dose 3 coverage (range, 61.2-87.7%) was markedly lower for Indigenous than non-Indigenous 12-year-olds in all jurisdictions, except for girls in NSW (82.6% v 83.6%). CONCLUSION: HPV vaccine coverage is high, but course completion is generally lower for Indigenous adolescents. Strategies for improving completion rates for Indigenous Australians are needed to end the higher burden of cervical cancer among Indigenous than non-Indigenous women.

Current antenatal pertussis vaccination guidelines miss preterm infants: An epidemiological study from the Northern Territory.

IMPORTANCE: Assessing gaps in antenatal pertussis vaccination to increase coverage. INTRODUCTION: Antenatal pertussis vaccination has been proven effective in reducing pertussis disease in infants. Current guidelines recommend maternal pertussis vaccination from 28 weeks gestation. The aim of this study is to determine antenatal pertussis vaccination coverage in the Northern Territory and potential socio-demographic factors affecting uptake, using validated birth and immunisation data. METHODS: Cross-sectional population study including all viable births (from 24 weeks gestation) in Northern Territory public hospitals in 2016. RESULTS: There were 3392 viable delivery episodes in 2016 with 48.9% coverage against maternal pertussis based on current guidelines. Mothers <35 years old were more likely to receive antenatal vaccination (adjusted odds ratio (aOR) = 1.26, CI 1.035-1.52, P = 0.021). Pertussis vaccination coverage for preterm births was low at 0% for extreme, 18.86% for very preterm and 39.8% for moderate preterm births, with an overall coverage of 33.5% for all preterm births. Term births were two times more likely than preterm births to have had mothers receive an antenatal diphtheria toxoid, tetanus toxoid and acellular pertussis vaccine (aOR = 1.957, CI 1.53-2.50, P < 0.001). CONCLUSIONS: A significant proportion (66.5%) of preterm babies are not benefiting from protection against pertussis with the current pertussis vaccination policy from 28 weeks gestation. As timing of birth cannot be predetermined, a review of safety and acceptability of pertussis vaccine administration in the second trimester is needed. Implementation of pertussis vaccination from 20 weeks gestation will provide a wider vaccination period and maximise the protection of all infants including pre-term infants from pertussis.

Adolescent school-based vaccination in Australia.

Adolescents have become an increasingly prominent target group for vaccination in Australia and other developed countries. Over the past decade, voluntary school-based vaccination programs have evolved to become the primary method of delivering adolescent vaccines funded under Australia's National Immunisation Program (NIP). These programs operate at a state and territory level and offer NIP vaccines to adolescents in specific school grades using local teams of trained vaccine providers. This paper summarises the current operation of voluntary school-based vaccination programs in Australia. Information was obtained through a literature review, semi-structured interviews with those managing and implementing school-based vaccination programs in each jurisdiction and a review of program resources. Available coverage data was obtained from each state or territory. Vaccines are delivered at the school, during school hours, and typically target late primary or early secondary school grades. Written parental consent is required for any vaccine to be administered. Operation of the programs is influenced by various factors at the school and provider level. Despite variability in program implementation, collection and analysis of coverage data, comparable coverage has been achieved across all states and territories. Coverage is higher than that reported by other countries where adolescent vaccines are mandated for school entry or available only through community vaccination providers. Voluntary school-based vaccination programs are an established mechanism for the delivery of adolescent vaccines in Australia and vaccines offered will continue to evolve in light of national recommendations. Current gaps in evidence include a detailed understanding of the influence of procedural factors on uptake, the best ways to maximise consent form return and, standardisation of coverage data reporting.

Interim estimates of human papillomavirus vaccination coverage in the school-based program in Australia.

In November 2006, the Australian Government announced the National HPV Vaccination Program, consisting of a course of prophylactic human papillomavirus (HPV) vaccine for all Australian females aged 12-26 years. Females aged 12-18 years are vaccinated through school-based programs. The school-based component commenced in April 2007, with the school years targeted varying across jurisdictions. Each jurisdiction maintains comprehensive records of HPV doses delivered in the school-based programs although how this is captured varies. This report presents interim coverage estimates for Year 1 (2007) of the program. Both New South Wales and Victoria achieved coverage of 70% or more among almost all school cohorts vaccinated in the program. Some of the variation in coverage achieved may reflect different levels of experience with school-based programs, and varying methods for school-based vaccine delivery and recording of doses administered. Except for some doses in South Australia, these interim coverage estimates do not include catch-up doses delivered by general practitioners or persons who were vaccinated prior to the onset of the program. Therefore, these data should be considered minimum estimates of coverage. The 1st year of the school-based HPV vaccination program should be considered a success, given time and resource constraints. Public sector immunisation providers across Australia should be commended for planning and implementing a new national immunisation program in approximately 4 months.

Vegetation fires, particulate air pollution and asthma: a panel study in the Australian monsoon tropics.

We examined the relationship between particulate matter (PM) <10 and <2.5 microns in diameter (PM10 and PM2.5) generated by vegetation fires and daily health outcomes in 251 adults and children with asthma over a 7-month period. Data were analysed using generalized estimating equations adjusted for potential environmental confounders, autocorrelation, weekends and holidays. PM10 ranged from 2.6 - 43.3 microg m-3and was significantly associated with onset of asthma symptoms, commencing oral steroid medication, the mean daily symptom count and the mean daily dose of reliever medication. Similar results were found for PM2.5. No associations were found with the more severe outcomes of asthma attacks, increased health care attendances or missed school/work days. These results help fill a gap in the evidence about the population health impacts of lower levels of pollution characteristic of deliberate landscape burning to control fuel loads versus the better documented risks of more intense and severely polluting wildfires.

Intussusception in the Northern Territory: the incidence is low in Aboriginal and Torres Strait Islander children.

AIM: To describe the epidemiology, immunisation status and management of children with intussusception in the Northern Territory (NT), 1993-2003. METHODS: Intussusception data were obtained from all NT hospitals using the International Classification of Diseases (ICD 9/10) codes for children under 18 years of age between 1993 and 2003. Medical records of these children were used to collect information on demographics, admission date, clinical symptoms, signs and management. Immunisation data were obtained from the NT immunisation register. The NT mortality database was reviewed for deaths from intussusception in children between 1993 and 2003. One death in an Aboriginal and Torres Strait Islander child was found in the NT mortality database. Medical records for this child were destroyed and so the case definition for intussusception used in this study was not fulfilled and the child was excluded. RESULTS: Intussusception proven by radiological or surgical means was identified in 23 children from hospital records. The incidence for children with intussusception in NT is 0.65/1000 live births. The incidence of intussusception was lower in Aboriginal and Torres Strait Islander children (0.16/1000 live births) than in non-Aboriginal and Torres Strait Islander children (0.92/1000 live births) (P < 0.01). CONCLUSION: The incidence of intussusception in the NT is similar to other developed countries but Aboriginal and Torres Strait Islander children have a very low incidence of intussusception. Intussusception is a rare event in the NT and will require a sensitive surveillance system to detect any potential increased risk of intussusception after the introduction of a new rotavirus vaccine.