Assessing the effects of SARS-CoV-2 vaccination on the risk of household transmission during delta variant circulation: a population-based data linkage cohort study.

Background: Data on SARS-CoV-2 vaccine effectiveness to reduce transmission of infection in household settings are limited. We examined the effects of SARS-CoV-2 vaccines on Delta variant transmission within households in an infection-naïve population. Methods: This was a population-based data linkage cohort study in the Greater Sydney Metropolitan Area, New South Wales, Australia based on cases observed in June-November 2021. In households with ≥1 confirmed COVID-19 case, we calculated adjusted odds ratios (aOR) and 95% Confidence Intervals (95% CI) for the risk of SARS-CoV-2 transmission, by vaccination status (unvaccinated, partially vaccinated, fully vaccinated, or waning) and type of vaccines (mRNA or vector-based) received by both index cases and household contacts. Findings: In 20,651 households with a single index case, 18,542 of 72,768 (25%) household contacts tested PCR-positive ≤14 days after their respective index case. Household contacts with partial, full, or waning mRNA vaccination had aORs of 0.46 (95% CI 0.40-0.52), 0.36 (95% CI 0.32-0.41) and 0.64 (95% CI 0.51-0.80) compared to unvaccinated contacts, while for vector vaccines the corresponding aORs were 0.77 (95% CI 0.67-0.89), 0.65 (95% CI 0.55-0.76), and 0.64 (95% CI 0.39-1.05). Full mRNA-vaccination in index cases compared to non-vaccination was associated with aORs between 0.09 and 0.21 depending on the vaccination status of household contacts. Interpretation: Full vaccination of household contacts reduced the odds to acquire infection with the SARS-CoV-2 Delta variant in household settings by two thirds for mRNA vaccines and by one third for vector vaccines. For index cases, being fully vaccinated with an mRNA vaccine reduced the odds of onwards transmission by four-fifths compared to unvaccinated index cases. Full vaccination offered stronger protection than partial vaccination, particularly for mRNA vaccines, but with reduced effects when the last vaccination preceded exposure by ≥3 months. Funding: New South Wales Ministry of Health.

Seroprevalence of Japanese encephalitis virus-specific antibodies in Australia following novel epidemic spread: protocol for a national cross-sectional study.

INTRODUCTION: Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus that causes encephalitis and other morbidity in Southeast Asia. Since February 2022, geographically dispersed JEV human, animal and vector detections occurred on the Australian mainland for the first time. This study will determine the prevalence of JEV-specific antibodies in human blood with a focus on populations at high risk of JEV exposure and determine risk factors associated with JEV seropositivity by location, age, occupation and other factors. METHOD: Samples are collected using two approaches: from routine blood donors (4153 samples), and active collections targeting high-risk populations (convenience sampling). Consent-based sampling for the latter includes a participant questionnaire on demographic, vaccination and exposure data. Samples are tested for JEV-specific total antibody using a defined epitope-blocking ELISA, and total antibody to Australian endemic flaviviruses Murray Valley encephalitis and Kunjin viruses. ANALYSIS: Two analytic approaches will occur: descriptive estimates of seroprevalence and multivariable logistic regression using Bayesian hierarchical models. Descriptive analyses will include unadjusted analysis of raw data with exclusions for JEV-endemic country of birth, travel to JEV-endemic countries, prior JEV-vaccination, and sex-standardised and age-standardised analyses. Multivariable logistic regression will determine which risk factors are associated with JEV seropositivity likely due to recent transmission within Australia and the relative contribution of each factor when accounting for effects within the model. ETHICS: National Mutual Acceptance ethical approval was obtained from the Sydney Children's Hospitals Network Human Research Ethics Committee (HREC). Local approvals were sought in each jurisdiction. Ethical approval was also obtained from the Australian Red Cross Lifeblood HREC. DISSEMINATION: Findings will be communicated to participants and their communities, and human and animal health stakeholders and policy-makers iteratively and after final analyses. Understanding human infection rates will inform procurement and targeted allocation of limited JEV vaccine, and public health strategies and communication campaigns, to at-risk populations.

Effectiveness of bivalent COVID-19 boosters against COVID-19 mortality in people aged 65 years and older, Australia, November 2022 to May 2023.

We followed 4,081,257 Australian adults aged ≥ 65 years between November 2022 and May 2023 for COVID-19-specific mortality, when recombinant SARS-CoV-2 Omicron lineages (predominantly XB and XBB) as well as BA.2.75 were circulating. Compared with a COVID-19 booster targeting ancestral SARS-CoV-2 given > 180 days earlier, the relative vaccine effectiveness against COVID-19 death of a bivalent (ancestral/BA.1 or ancestral/BA.4-5) booster given 8 to 90 days earlier was 66.0% (95%CI: 57.6 to 72.2%) and that of a monovalent ancestral booster given 8 to 90 days earlier was 44.7% (95%CI: 23.9 to 59.7%).

Superior immunogenicity of mRNA over adenoviral vectored COVID-19 vaccines reflects B cell dynamics independent of anti-vector immunity: Implications for future pandemic vaccines.

Both vector and mRNA vaccines were an important part of the response to the COVID-19 pandemic and may be required in future outbreaks and pandemics. The aim of this study was to validate whether immunogenicity differs for adenoviral vectored (AdV) versus mRNA vaccines against SARS-CoV-2, and to investigate how anti-vector immunity and B cell dynamics modulate immunogenicity. We enrolled SARS-CoV-2 infection-naïve health care workers who had received two doses of either AdV AZD1222 (n = 184) or mRNA BNT162b2 vaccine (n = 274) between April and October 2021. Blood was collected at least once, 10-48 days after vaccine dose 2 for antibody and B cell analyses. Median ages were 42 and 39 years, for AdV and mRNA vaccinees, respectively. Surrogate virus neutralization test (sVNT) and spike binding antibody titres were a median of 4.2 and 2.2 times lower, respectively, for AdV compared to mRNA vaccinees (p < 0.001). Median percentages of memory B cells that recognized fluorescent-tagged spike and RBD were 2.9 and 8.3 times lower, respectively for AdV compared to mRNA vaccinees. Titres of IgG reactive with human adenovirus type 5 hexon protein rose a median of 2.2-fold after AdV vaccination but were not correlated with anti-spike antibody titres. Together the results show that mRNA induced substantially more sVNT antibody than AdV vaccine, which reflected greater B cell expansion and targeting of the RBD rather than an attenuating effect of anti-vector antibodies. ClinicalTrials.gov Identifier: NCT05110911.

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

Background: Few studies have examined effectiveness of COVID-19 vaccines against COVID-19 and all-cause mortality across different pandemic periods in 2022. Methods: 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. Findings: 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%). Interpretations: 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. Funding: This study was funded by the Health Economics Research Division in the Australian Government Department of Health and Aged Care.

Summary of National Surveillance Data on Vaccine Preventable Diseases in Australia, 2016-2018 Final Report.

Erratum Two tables within this report, as originally published, contained errors which are notified and corrected here.

ATAGI 2023 Annual Statement on Immunisation.

The Australian Technical Advisory Group on Immunisation (ATAGI) 2023 Annual Statement on Immunisation is the third publication in this series. It highlights the key successes, trends and challenges in the use of vaccines and control of vaccine preventable diseases (VPDs) in Australia in 2022. It also signals ATAGI's priority actions for addressing key issues for 2023 and beyond.

Annual immunisation coverage report 2021.

Introduction: 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. Children: '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. Adolescents: 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. Adults: 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. Conclusions: 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.

The clinicopathological features of thrombosis with thrombocytopenia syndrome following ChAdOx1-S (AZD1222) vaccination and case outcomes in Australia: a population-based study.

Background: Thrombosis with thrombocytopenia syndrome (TTS) associated with viral vector COVID-19 vaccines, including ChAdOx1-S (AstraZeneca AZD1222) vaccine, can result in significant morbidity and mortality. We report the clinicopathological features of TTS following ChAdOx1-S vaccination and summarise the case outcomes in Australia. Methods: In this cohort study, patients diagnosed with TTS in Australia between 23 March and 31 December 2021 were identified according to predefined criteria. Cases were included if they met the Therapeutic Goods Administration (TGA) probable and confirmed case definitions and were reclassified using Centres for Disease Control and Prevention (CDC) definition for analysis. Data were collected on patient baseline characteristics, clinicopathological features, risk factors, treatment and outcomes. Findings: A total of 170 TTS cases were identified, with most occurring after the first dose (87%) of ChAdOx1-S. The median time to symptom onset after vaccination and symptom onset to admission was 11 and 2 days respectively. The median age of cases was 66 years (interquartile range 55-74). All except two patients received therapeutic anticoagulation and 66% received intravenous immunoglobulin. Overall, 85.3% of cases were discharged home after a median hospitalisation of 6 days, 9.4% required ongoing rehabilitation and 5.3% died. Eight deaths were related to TTS, with another dying from an unrelated condition while receiving treatment for TTS. Deaths occurred more commonly in those classified as Tier 1 according to the CDC definition and were associated with more severe thrombocytopenia and disease-related haemorrhage. Interpretation: TTS, while rare, can be severe and have catastrophic outcomes in some individuals. In Australia, the mortality rate was low compared to that reported in other high-income countries. Almost all received therapeutic anticoagulation with no bleeding complications and were successfully discharged. This emphasises the importance of community education and an established pathway for early recognition, diagnosis and treatment of TTS. Funding: Australian Commonwealth Department of Health and Aged Care. H.A Tran, N. Wood, J. Buttery, N.W. Crawford, S.D. Chunilal, V.M. Chen are supported by Medical Research Future Funds (MRFF) grant ID 2015305.

Coverage and predictors of influenza and pertussis vaccination during pregnancy: a whole of population-based study.

BACKGROUND: Respiratory infections including influenza and pertussis are associated with significant morbidity and mortality in mothers and newborns. Vaccination during pregnancy against influenza and pertussis is recommended for all women but data on uptake in Australia is limited. METHODS: We conducted a retrospective population-based cohort study in Australia's largest state, New South Wales (NSW), using a Perinatal Data Collection (PDC). Data included demographic, pregnancy, and birth details including pertussis and influenza vaccination during pregnancy for all women giving birth between 01 January 2016 and 31 December 2020. We used descriptive statistics to assess uptake of influenza and pertussis vaccination during pregnancy and Poisson loglinear regression to estimate associations between maternal characteristics and vaccine receipt. RESULTS: During 2016-2020, there were 477,776 births (mean maternal age 32.25 years). In 176,255 (36.9%) births the mother received both vaccines; 202,922 (42.5%) influenza and 315,620 (66.1%) pertussis vaccine. From 2016 to 2020, reported coverage increased from 26.7% to 58.7% for influenza and 43.1% to 78.8% for pertussis, respectively. After adjustment, characteristics associated with lower likelihood of receiving influenza and pertussis vaccination included: younger age (<30 years), being born in Australia/New Zealand, from lower socio-economic strata, having previous pregnancies, being later to first antenatal care, utilising the public hospital care model, smoking, having chronic hypertension and BMI > 25 kg/m2. CONCLUSIONS: While reported coverage of both influenza and pertussis vaccine in birthing women in NSW has increased over time, disparities in coverage exist and they highlight areas where evidence-based interventions to improve maternal vaccination could be targeted.

Comparative effectiveness of four COVID-19 vaccines, BNT162b2 mRNA, mRNA-1273, ChAdOx1 nCov-19 and NVX-CoV2373 against SARS-CoV-2 B.1.1.529 (Omicron) infection.

BACKGROUND: There is limited data directly comparing the effectiveness of different COVID-19 vaccines. METHODS: We compared rates of SARS-CoV-2 Omicron BA.1/2 infection during March to May 2022 in Australian adults who had received one of four COVID-19 vaccines in the last 14-63 days as either a primary course or a booster dose using Cox proportional hazards models adjusting for age and other characteristics. RESULTS: As a primary course, over 2318 person-years and 1033 infections, compared to recipients of BNT162b2 mRNA vaccine, adjusted hazard ratios for SARS-CoV-2 infection were 1.03 (95%CI 0.82-1.30), 1.19 (0.95-1.49), 1.70 (1.46-1.97) for respectively mRNA-1273, ChAdOx-1 nCov-19 and NVX-CoV2373. For the booster dose, over 154,984 person-years and 93,580 infections the respective adjusted hazard ratios compared to BNT162b2 mRNA vaccine were 1.02 (95%CI 1.00-1.04), 1.20 (1.10-1.32), 1.39 (1.20-1.60). CONCLUSIONS: Our findings suggest relatively higher effectiveness of ancestral strain mRNA vaccines against SARS-CoV-2 Omicron infection than viral vector and protein subunit vaccines and provide clinical confirmation of immunological data on differences in COVID-19 vaccine performance.

Corrigendum to "Lower risk of multi-system Inflammatory Syndrome in Children (MIS-C) with the Omicron variant" [The Lancet Regional Health - Western Pacific 27 (2022) 100604].

[This corrects the article DOI: 10.1016/j.lanwpc.2022.100604.].

Seroprevalence and prevention of hepatitis B, measles and rubella among healthcare workers in Dili, Timor-Leste.

Introduction: The World Health Organisation recommends that healthcare workers (HCWs) are immune to measles and rubella, and those at risk of exposure are offered the hepatitis B vaccine. No formal programme for occupational assessment and provision of vaccinations to HCWs currently exists in Timor-Leste. Methods: A cross-sectional study was undertaken to determine the seroprevalence of hepatitis B, measles and rubella among HCWs in Dili, Timor-Leste. All patient-facing employees at three healthcare institutions during April-June 2021 were invited to participate. Epidemiological data were collected by interview-questionnaire and a serum sample was collected by phlebotomy and analysed at the National Health Laboratory. Participants were contacted to discuss their results. Relevant vaccines were offered to seronegative individuals and those with active hepatitis B infection were referred for further assessment and management in a hepatology clinic as per national guidelines. Results: Three-hundred-and-twenty-four HCWs were included (representing 51.3% of all eligible HCWs working at the three participating institutions). Sixteen (4.9%; 95% CI: 2.8-7.9%) had active hepatitis B infection, 121 (37.3%; 95% CI: 32.1-42.9%) had evidence of previous (cleared) hepatitis B infection, 134 (41.4%; 95% CI: 35.9-46.9%) were hepatitis B seronegative, and 53 (16.4%; 95% CI: 12.5-20.8%) had been vaccinated. Two-hundred-and-sixty-seven (82.4%; 95% CI: 77.8-86.4%) and 306 (94.4%; 95% CI: 91.4-96.7%) individuals exhibited antibodies to measles and rubella, respectively. Interpretation: There are significant immunity gaps and a high prevalence of hepatitis B infection among HCWs in Dili Municipality, Timor-Leste. Routine occupational assessment and targeted vaccination of this group would be beneficial and should include all types of HCWs. This study provided an opportunity to develop a programme for the occupational assessment and vaccination of HCWs and forms the template for a national guideline. Funding: This work was supported by the Department of Foreign Affairs and Trade, Australian Government [Complex Grant Agreement Number 75889].

Comparative B cell and antibody responses induced by adenoviral vectored and mRNA vaccines against COVID-19.

Both vector and mRNA vaccines were an important part of the response to the COVID-19 pandemic and may be required in future outbreaks and pandemics. However, adenoviral vectored (AdV) vaccines may be less immunogenic than mRNA vaccines against SARS-CoV-2. We assessed anti-spike and anti-vector immunity among infection-naïve Health Care Workers (HCW) following two doses of AdV (AZD1222) versus mRNA (BNT162b2) vaccine. 183 AdV and 274 mRNA vaccinees enrolled between April and October 2021. Median ages were 42 and 39 years, respectively. Blood was collected at least once, 10-48 days after vaccine dose 2. Surrogate virus neutralization test (sVNT) and spike binding antibody titres were a median of 4.2 and 2.2 times lower, respectively, for AdV compared to mRNA vaccinees (p<0.001). Median percentages of memory B cells that recognized fluorescent-tagged spike and RBD were 2.9 and 8.3 times lower, respectively for AdV compared to mRNA vaccinees. Titres of IgG reactive with human Adenovirus type 5 hexon protein rose a median of 2.2-fold after AdV vaccination but were not correlated with anti-spike antibody titres. Together the results show that mRNA induced substantially more sVNT antibody than AdV vaccine due to greater B cell expansion and targeting of the RBD. Pre-existing AdV vector cross-reactive antibodies were boosted following AdV vaccination but had no detectable effect on immunogenicity.

Complex intervention to promote human papillomavirus (HPV) vaccine uptake in school settings: A cluster-randomized trial.

Using a cluster-randomized trial design, we aimed to evaluate a complex intervention to increase uptake of human papillomavirus (HPV) vaccination in schools. The study was undertaken in high schools in Western Australia and South Australia between 2013 and 2015 with adolescents aged 12-13 years. Interventions included education, shared decision-making, and logistical strategies. The main outcome was school vaccine uptake. Secondary outcomes included consent forms returned and mean time to vaccinate 50 students. We hypothesised that a complex intervention would increase 3-dose HPV vaccine uptake. We recruited 40 schools (21 intervention, 19 control) with 6, 967 adolescents. There was no difference between intervention and control (3-dose mean 75.7% and 78.9%, respectively). Following adjustment for baseline covariates, absolute differences in coverage in favour of the intervention group were: dose 1, 0.8% (95% CI, -1.4,3.0); dose 2, 0.2% (95% CI, -2.7, 3.1); dose 3, 0.5% (95% CI, -2.6, 3.7). The percentage of returned consent forms in intervention schools (91.4%) was higher than in control schools (difference: 6%, 95% CI, 1.4, 10.7). There was a shorter mean time to vaccinate 50 students at dose 3. The difference for dose 3 was 110 min (95% CI, 42, 177); for dose 2, 90 min (95% CI, -15, 196); and dose 1, 28 min (95% CI, -71, 127). Logs revealed the inconsistent implementation of logistical strategies. The intervention had no impact on uptake. Inadequate resourcing for logistical strategies and advisory board reluctance toward strategies with potential financial implications impacted the implementation of logistical components. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry, ACTRN12614000404628, 14.04.2014. The study protocol was published in 2015 before data collection was finalised (Skinner et al., 2015). THE HPV.EDU STUDY GROUP: We would like to acknowledge the contributions to this study by members of the HPV.edu Study Group, including: Professor Annette Braunack-Mayer: Australian Centre for Health Engagement, Evidence and Values, School of Health and Society, Faculty of Arts, Social Sciences and Humanities, University of Wollongong, NSW, Australia; Dr. Joanne Collins: Women's and Children's Health Network and School of Medicine and Robinson Research Institute, University of Adelaide, SA, Australia; Associate Professor Spring Cooper: School of Public Health, City University of New York (CUNY), New York, NY, USA; Heidi Hutton: Telethon Kids Institute, University of Western Australia, WA, Australia; Jane Jones: Telethon Kids Institute, University of Western Australia, WA, Australia; Dr. Adriana Parrella: Women's and Children's Health Network and School of Medicine and Robinson Research Institute, University of Adelaide, SA, Australia; and South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia; Associate Professor David G. Regan: The Kirby Institute for Infection and Immunity in Society, Faculty of Medicine, UNSW Sydney, NSW, Australia; Professor Peter Richmond: Perth Children's Hospital, Child and Adolescent Health Service, Western Australia, Wesfarmers Centre of Vaccines and Infectious Diseases, Telethon Kids Institute, WA, Australia, and School of Medicine, University of Western Australia, Perth, WA, Australia; Dr. Tanya Stoney: Telethon Kids Institute, University of Western Australia, WA, Australia. Contact for the HPV.edu study group: Cristyn.Davies@sydney.edu.au or Rachel.Skinner@sydney.edu.au.

Short-term Adverse Events Following Immunization With Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN) Vaccine for Mpox.

This study uses data collected by Australia's vaccine safety surveillance system to examine the adverse event profile of the modified vaccinia Ankara­Bavarian Nordic vaccine.

Influenza and pertussis vaccine coverage in pregnancy in Australia, 2016-2021.

Vaccination in pregnancy is the best strategy to reduce complications from influenza or pertussis infection in infants who are too young to be protected directly from vaccination. Pregnant women are also at risk of influenza complications preventable through antenatal vaccination. Both vaccines are funded under the National Immunisation Program for pregnant women in Australia, but coverage is not routinely reported nationally. We reviewed all reported Australian maternal influenza and pertussis vaccine coverage data for the period 2016-2021, to identify gaps and information needs. Maternal influenza vaccine coverage was suboptimal at < 58% for 2016-2018, with higher coverage of 62-75% reported in two states (Victoria and Western Australia) for 2019-2021. Maternal pertussis vaccine coverage from 2016 was generally higher than for influenza at > 70%, with the highest jurisdictional coverage of 89% reported in Western Australia in 2020. Vaccination rates were often suboptimal among First Nations pregnant women and up to 20% lower than among non-First Nations Australian women; while data were limited, coverage was low among culturally and linguistically diverse women and among women of lower socio-economic status. Jurisdictional perinatal data collections were the best source of information on antenatal vaccine coverage but were only available for a minority of the population; a nationally consistent systematic approach is lacking. Timely and comprehensive data are needed to provide feedback to improve maternal vaccination coverage, particularly among groups with higher risk and/or low uptake, and as new vaccines are recommended, including COVID-19 vaccination.

Vaccine Preventable Disease Seroprevalence in a Nationwide Assessment of Timor-Leste (VASINA-TL): study protocol for a population-representative cross-sectional serosurvey.

INTRODUCTION: Historic disruption in health infrastructure combined with data from a recent vaccine coverage survey suggests there are likely significant immunity gaps to vaccine preventable diseases and high risk of outbreaks in Timor-Leste. Community-based serological surveillance is an important tool to augment understanding of population-level immunity achieved through vaccine coverage and/or derived from prior infection. METHODS AND ANALYSIS: This national population-representative serosurvey will take a three-stage cluster sample and aims to include 5600 individuals above 1 year of age. Serum samples will be collected by phlebotomy and analysed for measles IgG, rubella IgG, SARS-CoV-2 antispike protein IgG, hepatitis B surface antibody and hepatitis B core antigen using commercially available chemiluminescent immunoassays or ELISA. In addition to crude prevalence estimates and to account for differences in Timor-Leste's age structure, stratified age-standardised prevalence estimates will be calculated, using Asia in 2013 as the standard population. Additionally, this survey will derive a national asset of serum and dried blood spot samples which can be used for further investigation of infectious disease seroepidemiology and/or validation of existing and novel serological assays for infectious diseases. ETHICS AND DISSEMINATION: Ethical approval has been obtained from the Research Ethics and Technical Committee of the Instituto Nacional da Saúde, Timor-Leste and the Human Research Ethics Committee of the Northern Territory Department of Health and Menzies School of Health Research, Australia. Co-designing this study with Timor-Leste's Ministry-of-Health and other relevant partner organisations will allow immediate translation of findings into public health policy, which may include changes to routine immunisation service delivery and/or plans for supplementary immunisation activities.

ATAGI Targeted Review 2021: the national COVID-19 vaccination program.

Abstract: The overarching goal of the Australian coronavirus disease 2019 (COVID-19) vaccination program has been to protect all people in Australia from the harm caused by the novel coronavirus SARS-CoV-2. This review reflects on the role of the Australian Technical Advisory Group on Immunisation (ATAGI) in the national COVID-19 vaccination program, in terms of the initial programmatic and clinical recommendations in the evolving context of evidence relating to the disease and vaccines, epidemiology, and the program rollout. To fulfil the obligation to provide evidence-based advice to the Minister for Health and Aged Care on the safe, effective and equitable use of COVID-19 vaccines, ATAGI has worked closely with other agencies and committees such as the Therapeutic Goods Administration (TGA) and the Communicable Diseases Network Australia. ATAGI recommendations have sought to optimise the use of the available vaccine doses in achieving the objectives of preventing serious illness and death from COVID-19 while addressing any emerging safety signals following program commencement on 22 February 2021. As of mid-November 2021, the use of COVID-19 vaccines in children aged 5 to 11 years was being considered by the TGA and ATAGI; and emerging evidence, in areas such as use of heterologous vaccine schedules and co-administration with other vaccines, was under review. Despite unprecedented challenges which the delivery of mass COVID-19 vaccination presented to health systems globally, in Australia much was achieved in 2021 with over 90% coverage for primary doses in the vaccine-eligible population. Evaluation, using high quality data and assessment methods, of vaccination program outcomes-such as coverage, vaccine effectiveness and impact-is key to determine whether program objectives have been achieved and where gaps remain. Reflecting on the lessons learned so far would help further improve the national COVID-19 vaccination program and would also benefit programs for other routine vaccines and planning for future pandemics.