The Case for Assessing the Drivers of Measles Vaccine Uptake.

Global measles cases are on the rise following disruptions to routine immunisation programs during the COVID-19 pandemic, with devastating consequences. According to the World Health Organization, the behavioural and social drivers of vaccination include what people think and feel about vaccines, social processes, motivation to vaccinate and practical barriers to vaccination. However, the drivers of measles vaccine uptake are not necessarily the same as those for other childhood vaccines, and we lack data on how these drivers specifically have changed during and since the COVID-19 pandemic. Without accurately measuring the behavioural and social drivers for measles vaccination, and ideally measuring them serially over time, countries cannot design, target and implement interventions that effectively increase and sustain measles vaccine coverage. This paper outlines what is and is not known about the behavioural and social drivers of measles vaccination and provides recommendations for improving their post-pandemic assessment.

Comparison of parent-reported motivators of non-vaccination for children 5-11 years old in Australia and Canada: Results of the iCARE study.

BACKGROUND: Despite COVID-19 infection being less severe in children compared to adults, vaccination for children from the age of 6 months onwards is recommended in many countries to reduce symptom severity and prevent severe disease. However, vaccination against COVID-19 for children remains controversial and uptake has been low. AIMS: To assess and compare the rate of change of parent-reported COVID-19 vaccine uptake in children aged 5 to 11 years and motivators of vaccine acceptance and non-vaccination among parents/guardians in Canada and Australia. METHODS: As part of the iCARE study, two cross-sectional representative samples in Canada and Australia were collected between May 20 and September 12, 2022 (i.e., 5 and 9 months after the COVID-19 vaccine rollout for children 5-11 years) using online panels. Parents/guardians reported the vaccine status of their children and motivators for vaccine acceptance and non-vaccination. General linear models were used to estimate differences between countries in terms of vaccine uptake and motivators across time. RESULTS: Parent-reported vaccine uptake for children 5-11 years didn't increase over the study period (T1 = 87 %,T2 = 86 %; OR = 0.83; 95 %CI = 0.45-1.54) and was overall lower in Canada (60.8 %) compared to Australia (71.6 %)(OR = 0.56; 95 %CI = 0.33-0.96). In both countries the socioeconomic characteristics of parents who didn't vaccinate their children were similar and having information on either the short- or long-term side effects of the vaccine were important motivators. However, vaccine effectiveness was more important in Canada and trust in the company that developed the vaccine and a recommendation from the child's doctor were more important motivators in Australia. CONCLUSION: Parent-reported vaccine uptake for children 5-11 years plateaued early in the vaccine rollout. The main motivators for parents of unvaccinated children varied between the two countries but information on vaccine safety and effectiveness were common to both countries. Findings may inform future tailored vaccine communication efforts and pandemic planning in Australia and Canada to optimize vaccine uptake for primary school children.

Acceptability of an asymptomatic COVID-19 screening program for schools in Victoria, Australia: a qualitative study with caregivers from priority populations.

BACKGROUND: An asymptomatic COVID-19 rapid antigen testing (RAT) screening program was implemented in Victorian schools in January 2022, to support keeping schools open throughout the pandemic. This study explored compliance with the program among caregivers from priority populations in Victorian mainstream and specialist schools. METHODS: We conducted semi-structured interviews between 7-31 March 2022 with caregivers of school-aged children participating in the RAT program in Victoria. Participants were asked about awareness, acceptability, compliance, frequency, and barriers to testing. Recordings were transcribed and deductively analysed using a framework approach. RESULTS: Fifty caregivers participated. They expressed confusion about the 'recommended' program, assuming it was mandatory. Caregivers wanted notification from schools of positive cases to increase motivation for compliance. Culturally and linguistically diverse (CALD) families were compliant; however, in-language resources were limited. Aboriginal or Torres Strait Islander (Koori) families tested less regularly and received information from their community rather than school. Caregivers of children living with disabilities reported behavioural challenges to testing, resulting in distress or non-compliance, and received non-specific information for their children. CONCLUSIONS: To increase engagement with future surveillance programs, caregivers need clarity about optionality, conducting tests, reporting results, and timely notification of cases. Requirements unique to each priority population include: accurate in-language information for CALD caregivers, community-led communication for Koori caregivers, tailored information, less testing, and flexibility for caregivers of children living with a disability. Keeping schools open and having tailored strategies to ensure equitable access for priority populations are essential for future pandemic management.

Development and validation of the Vaccine Barriers Assessment Tool for identifying drivers of under-vaccination in children under five years in Australia.

Data on routine childhood vaccination coverage can only tell us who is under-vaccinated; it cannot explain why vaccine coverage is low. Collecting data on the reasons behind under-vaccination is necessary to implement cost-effective strategies that address key barriers and target interventions appropriately. However, no instruments that measure both vaccine acceptance and access factors among parents of children <5 y have been validated in high-income countries. This study aims to develop and validate the Vaccine Barriers Assessment Tool (VBAT) for Australia. We applied three phases of mixed methods data collection and analysis. In Phase 1, we developed a comprehensive list of 80 items reflecting all potential parental barriers to childhood vaccination, derived from published literature and behavioral theory. Through cognitive interviews (n = 28), we refined this list to 45 items. In Phase 2, we conducted a two-wave online survey to test the reliability and validity of these items in an Australian sample of parents (n = 532) with structural equation modeling, further refining the list to 35 items. In Phase 3, we conducted a final parent survey (n = 156), administering these items along with the Parent Attitudes toward Childhood Vaccination (PACV) scale for comparison. We reviewed participants' immunization register data to assess the predictive validity of the proposed models. The final 6-item short form and 15-item long form Vaccine Barriers Assessment Tool assess access, communal benefit, personal risk, equity, commitment, social norms, and trust in health-care workers. It is being applied for national surveillance in Australia and will be adapted for additional populations and vaccines.

Community health workers' dissemination of COVID-19 information and services in the early pandemic response: a systematic review.

BACKGROUND: Community health workers (CHWs) had important roles mitigating the impact of the COVID-19 pandemic in vulnerable communities. We described how CHWs supported the dissemination of COVID-19 information and services during the early pandemic response. METHODS: Online article searches were conducted across five scientific databases, with review article reference lists hand searched to identify grey/unpublished literature. Articles were included if they reported on a program that engaged CHWs and aimed to prevent/control COVID-19. RESULTS: Nineteen relevant programs were identified from 18 included articles. CHWs were widely engaged in the pandemic response, especially in low- and middle-income countries and in vulnerable communities. CHWs' ability to effectively disseminate COVID-19 information/services was enabled by community trust and understanding community needs. CHWs were often underfunded and required to work in difficult conditions. Pre-existing services incorporating CHWs rapidly adapted to the new challenges brought by the pandemic. CONCLUSIONS: We recommend establishing programs that employ CHWs to disseminate health information and services in communities at-risk of misinformation and poor health outcomes during non-pandemic times. CHWs are well-placed to deliver interventions should an infectious disease outbreak arise. Having pre-existing trusted relationships between CHWs and community members may help protect vulnerable groups, including when outbreaks occur.

Evaluating a peer-to-peer health education program in Australian public housing communities during the COVID-19 pandemic.

BACKGROUND: The cohealth Health Concierge program operated in Melbourne, Australia from July 2020 to 30 June 2022. It provided peer-to-peer support to culturally and linguistically diverse residents of high-rise public housing. During this time, the COVID-19 public health response changed frequently and included movement restriction, testing and vaccination. We conducted a mixed-methods evaluation to determine the Health Concierge program's impact on residents' engagement with health services and public health activities. METHODS: The evaluation, informed by a Project Reference Group, used the RE-AIM framework. We analysed data from 20,901 routinely collected forms describing interactions between Concierges and residents from August 2021 to May 2022. Additional evaluation-specific data were collected between March and May 2022 in four housing estates; we surveyed 301 residents and conducted 32 interviews with residents, Concierges and program stakeholders. RESULTS: Concierges promoted COVID-safe behaviours; linked residents with support, testing and vaccination services; and disseminated up-to-date information. Of the 20,901 recorded interactions, 8,872 (42%) included Concierges providing support around COVID-19 vaccination. Most surveyed residents (191/301, 63%) reported speaking with a Concierge in the previous six months. The self-reported two-dose COVID-19 vaccine uptake was 94% (283/301). Some residents described having meaningful, appreciated conversations with Concierges, and some described superficial interactions. While residents initially welcomed the program, many felt it failed to evolve. Poorly defined management and hiring criteria led to variable program implementation. A need for bicultural workers to continue linking residents with services was discussed. CONCLUSIONS: Concierges' impact on residents may have contributed to high community uptake of COVID-19 testing and vaccination, and had benefits beyond the COVID-19 remit. We recommend the program be revised and continued to inform further preparedness planning and support service access generally. Program models such as this have potential to inform and reassure high-risk communities during a pandemic. In addition, such programs can help overcome vaccine hesitancy and promote protective health behaviours, regardless of whether a pandemic is currently occurring. Ensuring these programs remain responsive to the changing needs of end-users needs over time is imperative.

Influence of the COVID-19 pandemic on caregiver beliefs and experiences of routine childhood immunisation in Indonesia.

The COVID-19 pandemic contributed to significant health services declines in South-East Asia including Indonesia, which experienced a decline in routine immunisation of children. This study investigated the influence of the pandemic on the beliefs and experiences of caregivers of children related to routine immunisation. This study involved a cross-sectional survey among 1399 caregivers of children aged 0-24 months in Central Java and West Nusa Tenggara provinces from March-April 2022. Data on beliefs and experiences of childhood immunizations were captured using core items from the WHO/UNICEF Behavioural and Social Drivers of Immunization (BeSD) survey. Bivariate and multivariate logistic regression analyses identified factors associated with uptake of routine immunisations. While nearly all caregivers (95.7%) reported wanting their child to receive all recommended routine immunisations, only 40.3% of children aged 2-24 months were up-to-date with all vaccines for age. Factors associated with up-to-date included higher parental education (aOR: 1.76, 95% CI 1.02-3.05), higher household income (aOR: 1.54, 95% CI 1.09-2.18), and caregivers who found it moderately or very easy to get immunisations (aOR: 2.26/2.22, 95% CI 1.06-4.83/1.06-4.69). Recovery efforts should prioritise responding to the factors associated with immunisation status (e.g., perceived ease of access) and on families experiencing disadvantage (e.g., caregivers with lower education and household income) to ensure protections against future outbreaks that are responsive to the context-specific needs and priorities of districts and communities.

Behavioural and social drivers of COVID-19 vaccination in Vietnam: a scoping review.

BACKGROUND: Understanding of the behavioural and social drivers (BeSD) of vaccination is key to addressing vaccine hesitancy and accessibility issues. Vietnam's national COVID-19 vaccination programme resulted in high uptake of primary doses among adults, but lower booster doses for adults and primary doses for 5-11 years. This scoping review assessed BeSD influencing COVID-19 vaccine uptake in Vietnam to design interventions on reaching the national vaccination targets. METHOD: We conducted a scoping review by searching PubMed, MedRxiv, LitCOVID, COVID-19 LOVE platform, WHO's COVID-19 research database and seven dominant Vietnamese language medical journals published in English or Vietnamese between 28 December 2019 and 28 November 2022. Data were narratively synthesised and summarised according to the four components of the WHO BeSD framework. The drivers were then mapped along the timeline of COVID-19 vaccine deployment and the evolution of the pandemic in Vietnam. RESULTS: We identified 680 records, of which 39 met the inclusion criteria comprising 224 204 participants. Adults' intention to receive COVID-19 vaccines for themselves (23 studies) ranged from 58.0% to 98.1%. Parental intention to vaccinate their under 11-year-old children (six studies) ranged from 32.8% to 79.6%. Key drivers of vaccination uptake were perceived susceptibility and severity of disease, perceived vaccine benefits and safety, healthcare worker recommendation, and positive societal perception. Commonly reported COVID-19 vaccines' information sources (six studies) were social and mainstream media (82%-67%), television (72.7%-51.6%) and healthcare workers (47.5%-17.5%). Key drivers of COVID-19 uptake remained consistent for both adults and children despite changes in community transmission and vaccine deployment. CONCLUSION: Key enablers of vaccine uptake for adults and children included perceived disease severity, perceived vaccine benefits and safety and healthcare worker recommendations. Future studies should assess vaccine communication targeted to these drivers, national policies and political determinants to optimise vaccine uptake.

Parent-Reported Child and Parent Quality of Life during COVID-19 Testing at an Australian Paediatric Hospital Outpatient Clinic: A Cross-Sectional Study.

Globally, we have seen a drop in adult and child quality of life (QOL) during the COVID-19 pandemic. However, little is known about adult or child QOL during the height of the pandemic in Australia and the impact of government-imposed restrictions, specifically attending school on-site versus home schooling. Our study aimed to establish if QOL in children and parents presenting to a Respiratory Infection Clinic in Victoria, Australia, for COVID-19 PCR testing differed from pre-pandemic population norms. We also explored whether on-site versus home schooling further impacted QOL. Following the child's test and prior to receiving results, consenting parents of children aged 6 to 17 years old completed the Child Health Utility 9 Dimension (CHU9D) instrument on their child's behalf. Parents of children aged birth to five years completed the EuroQOL 5-Dimension 5-Level (EQ-5D-5L) instrument on their own behalf (cross-sectional study). Data analyses utilised quantile regression, adjusting for the child's age, COVID-19 symptoms, gender and chronic health conditions. From July 2020 to November 2021, 2025 parents completed the CHU9D; the mean age for children was 8.41 years (±3.63 SD), and 48.4 per cent were female (n = 980/2025). In the same time period, 5751 parents completed the EQ-5D-5L; the mean age for children was 2.78 years (±1.74 SD), and 52.2 per cent were female (n = 3002/5751). Results showed that QOL scores were lower than pre-pandemic norms for 68 per cent of the CHU9D group and 60 per cent of the EQ-5D-5L group. Comparing periods of on-site to home schooling, there was no difference between the median QOL scores for both CHU9D (0.017, 95% CI -0.05 to 0.01) and EQ-5D-5L (0.000, 95% CI -0.002 to 0.002). Our large-scale study found that while QOL was reduced for children and parents at the point of COVID-19 testing during the pandemic, differing levels of government-imposed restrictions did not further impact QOL. These unique insights will inform decision-making in relation to COVID-19 and future pandemics.

Reducing COVID-19 Vaccine Decisional Conflict in Parents of 5-11-Year-Old Children in Australia: A Single Arm Pre-Post Study.

COVID-19 vaccine uptake among 5-11-year-olds is significantly lower than that of the 12+ age group. Some parents may have decided against vaccinating their children for COVID-19; others may be undecided and may be seeking more information to support their decision. We aimed to assess the effect of a decision support tool on parents' level of decisional conflict, vaccine hesitancy, and intention to vaccinate. We conducted a single-arm, cross-sectional online pre-post intervention survey of parents from Victoria, Australia, who had not yet vaccinated their 5-11-year-old child for COVID-19. We measured change in decisional conflict, intention, and hesitancy towards COVID-19 vaccines for children before and after viewing a decision support tool. We used logistic regression to identify characteristics associated with reduced decisional conflict. Between May and September 2022, 108 parents took part in the study. The tool reduced decision conflict in 25% (27/107) of parents, with reduced decisional conflict more likely among parents initially undecided about vaccinating, compared to parents who did not intend to vaccinate their child (OR, 12.58 95% CI 3.21 to 9.30). For most parents, hesitancy (83%, 90/108) and intention (89%, 96/108) remained the same. The decision support tool was modestly effective at reducing decisional conflict, particularly among undecided parents.

Interventions for increasing the uptake of immunisations in healthcare workers: A systematic review.

OBJECTIVE: This systemic review aimed to evaluate the effectiveness of interventions for increasing the uptake of immunisation in healthcare workers (HCWs) compared to no or alternative interventions. METHODS: A systematic review was undertaken (until March 2022) using a search strategy established a priori to capture studies that examined the effect of interventions on vaccination levels in HCWs. We included randomised controlled trials (RCT), cluster RCTs, controlled before-after (CBA) studies and interrupted time-series (ITS) studies. We described studies descriptively and synthesized results with a fixed-effect or random-effects model meta-analysis, where appropriate. The risk of bias was assessed for each study; the quality evidence per comparison was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE). RESULTS: We identified three RCTs, six cluster RCTs and four ITS studies. There was a diverse range of interventions; many included an educational component. Based on the evidence examined the following may be effective strategies in increasing the proportion of HCWs vaccinated: policy interventions, targeted and multicomponent strategies, tailored programs directed at management, physician delivered education with a vaccine 'champion' and individual decision analysis. Limited eligible studies restricted synthesis and interpretation of findings. No studies evaluated the effectiveness of legislation. Nor did we find studies evaluating the effectiveness of incentives on their own or studies focusing solely on improving access to vaccination. We judged all the studies as either unclear or high risk of bias. CONCLUSION: Few robust studies that evaluate interventions to increase vaccination in HCWs are available. A limitation of this systematic review is that interventions are diverse, poorly reported and few were sufficiently alike to combine in an evaluation. More research on the effects of interventions to increase vaccination in HCWs is required, this should address a variety of vaccines and not just influenza vaccination.

Impact of COVID-19 on routine childhood immunisations in low- and middle-income countries: A scoping review.

Routine vaccines are critical to child health. The COVID-19 pandemic significantly impacted essential health services, particularly in low-and middle-income countries (LMICs). We reviewed literature to determine the impact of COVID-19 on service delivery and uptake of routine childhood immunisation in LMICs. We reviewed papers published between March 2020 and June 2022 using a scoping review framework, and assessed each paper across the World Health Organisation health system strengthening framework. Our search identified 3,471 publications; 58 studies were included. One-quarter of studies showed routine childhood immunisation coverage declined (10% to 38%) between 2019 to 2021. Declines in the number of vaccine doses administered (25% to 51%), timeliness (6.2% to 34%), and the availability of fixed and outreach services were also reported. Strategies proposed to improve coverage included catch-up activities, strengthening supply chain and outreach services. Re-focusing efforts on increasing coverage is critical to improve child health and reduce the likelihood of disease outbreaks.

Factors influencing uptake of the COVID-19 vaccination among pregnant women in Australia: A cross-sectional survey.

BACKGROUND: Mounting evidence shows the risk of COVID-19 on perinatal outcomes, as well as the safety and efficacy of vaccination during pregnancy. However, little is known about vaccine uptake among pregnant women in Australia, including women who are culturally and linguistically diverse (CALD), and about sources of information pregnant women use when making decisions about vaccines. We aimed to determine the proportion of pregnant women who had been vaccinated and to identify factors associated with vaccine uptake or decline during pregnancy. METHOD: A cross-sectional, anonymous, online survey was conducted from October 2021 to January 2022 in two metropolitan hospitals in New South Wales, Australia. RESULTS: Of 914 pregnant women, 406 (44%) did not speak English at home. Overall, 101 (11%) received a vaccine prepregnancy and 699 (76%) during pregnancy. In the nonvaccinated cohort, 87 (76%) declined vaccination during pregnancy. The uptake was more than 87% among women during pregnancy who received information from government or health professional websites but 37% when received from personal blogs. The main reasons for vaccine uptake were (1) hearing that COVID-19 affects pregnant women, (2) being concerned about the COVID-19 outbreak, and (3) receiving vaccine recommendation from a general practitioner. In a multivariable logistic regression, three main factors associated with declining or feeling unsure about vaccination were (1) concerns about the safety of the COVID-19 vaccine, (2) lack of trust and being unsatisfied with the information received about COVID-19 vaccination during pregnancy, and (3) doubting the importance of COVID-19 vaccine. CONCLUSION: Clinicians play a critical role in counseling women to alleviate vaccine fear, support vaccine acceptance, and direct women to use reliable information sources, such as government and professional healthcare organizations, for information about vaccines.

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.

BACKGROUND: Influenza 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. METHODS: Pregnant 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. DISCUSSION: Behavioural 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 REGISTRATION: ClinicalTrials.gov Identifier NCT05613751. Registered on November 14, 2022.

Barriers to COVID-19 vaccination of migrant populations: A qualitative interview study of immunisation providers in Victoria, Australia.

INTRODUCTION: This study aimed to understand barriers and enablers, future strategies, communication approaches and resources needed for COVID-19 vaccination among migrant communities in Melbourne, Australia. MATERIAL AND METHODS: We interviewed 24 immunisation providers who deliver immunisation services to migrant populations in Melbourne. We used the WHO Behavioural and Social Drivers framework (underlined) to organise barriers and enablers to COVID-19 vaccination. RESULTS: Participants believed migrants had concerns about vaccine safety and efficacy and saw vaccines as minimally beneficial in the 'low COVID-19' environment of Australia (what people think and feel). Healthcare providers with established relationships within migrant communities played key roles in vaccine advocacy (social processes). Migrants' vaccine motivation was mediated by health literacy, institutional trust and previous experiences with health services. Practical issues included perceived lack of information on vaccine booking process and accessibility challenges. CONCLUSIONS: Strategies to increase migrant vaccine coverage should utilise immunisation providers with community links and trusted local vaccine ambassadors to engage and address community vaccine concerns.

Keeping kids in school: modelling school-based testing and quarantine strategies during the COVID-19 pandemic in Australia.

Background: In 2021, the Australian Government Department of Health commissioned a consortium of modelling groups to generate evidence assisting the transition from a goal of no community COVID-19 transmission to 'living with COVID-19', with adverse health and social consequences limited by vaccination and other measures. Due to the extended school closures over 2020-21, maximizing face-to-face teaching was a major objective during this transition. The consortium was tasked with informing school surveillance and contact management strategies to minimize infections and support this goal. Methods: Outcomes considered were infections and days of face-to-face teaching lost in the 45 days following an outbreak within an otherwise COVID-naïve school setting. A stochastic agent-based model of COVID-19 transmission was used to evaluate a 'test-to-stay' strategy using daily rapid antigen tests (RATs) for close contacts of a case for 7 days compared with home quarantine; and an asymptomatic surveillance strategy involving twice-weekly screening of all students and/or teachers using RATs. Findings: Test-to-stay had similar effectiveness for reducing school infections as extended home quarantine, without the associated days of face-to-face teaching lost. Asymptomatic screening was beneficial in reducing both infections and days of face-to-face teaching lost and was most beneficial when community prevalence was high. Interpretation: Use of RATs in school settings for surveillance and contact management can help to maximize face-to-face teaching and minimize outbreaks. This evidence supported the implementation of surveillance testing in schools in several Australian jurisdictions from January 2022.

Testing persuasive messages about booster doses of COVID-19 vaccines on intention to vaccinate in Australian adults: A randomised controlled trial.

INTRODUCTION: Achieving high COVID-19 vaccine booster coverage is an ongoing global challenge. Health authorities need evidence about effective communication interventions to improve acceptance and uptake. This study aimed to test effects of persuasive messages about COVID-19 vaccine booster doses on intention to vaccinate amongst eligible adults in Australia. METHODS: In this online randomised controlled trial, adult participants received one of four intervention messages or a control message. The control message provided information about booster dose eligibility. Intervention messages added to the control message, each using a different persuasive strategy, including: emphasising personal health benefits of booster doses, community health benefits, non-health benefits, and personal agency in choosing vaccination. After the intervention, participants answered items about COVID-19 booster vaccine intention and beliefs. Intervention groups were compared to the control using tests of two proportions; differences of ≥5 percentage points were deemed clinically significant. A sub-group analysis was conducted among hesitant participants. RESULTS: Of the 487 consenting and randomised participants, 442 (90.8%) completed the experiment and were included in the analysis. Participants viewing messages emphasising non-health benefits had the highest intention compared to those who viewed the control message (percentage point diff: 9.0, 95% CI -0.8, 18.8, p = 0.071). Intention was even higher among hesitant individuals in this intervention group compared to the control group (percentage point diff: 15.6, 95% CI -6.0, 37.3, p = 0.150). Conversely, intention was lower among hesitant individuals who viewed messages emphasising personal agency compared to the control group (percentage point diff: -10.8, 95% CI -33.0, 11.4, p = 0.330), although evidence in support of these findings is weak. CONCLUSION: Health authorities should highlight non-health benefits to encourage COVID-19 vaccine booster uptake but use messages emphasising personal agency with caution. These findings can inform communication message development and strategies to improve COVID-19 vaccine booster uptake. Clinical trial registration: Registered with the Australian New Zealand Clinical Trials Registry (ACTRN12622001404718); trial webpage: https://www.anzctr.org.au/ACTRN12622001404718.aspx.

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.