Herpes zoster (HZ) vaccine coverage and confidence in Italy: a Nationwide cross-sectional study, the OBVIOUS project.

BACKGROUND: Herpes Zoster is an age dependent disease and as such it represents a problem in the Italian social context, where the demographic curve is characterized by an overrepresentation of the elderly population. Vaccines against Herpes Zoster are available, safe and effective, however coverage remains sub-optimal. This study was therefore conducted to examine the variations in Herpes Zoster vaccine uptake and confidence across different regions in Italy. METHODS: This study utilized a cross-sectional computer-assisted web interview (CAWI) methodology. The survey was conducted by Dynata, an online panel provider, and involved 10,000 respondents recruited in Italy between April 11 and May 29, 2022. The sample was stratified based on geographic region, gender, and age group. Data management adhered to European Union data protection regulations, and the survey covered demographics, living conditions, and vaccination against herpes zoster (HZ), following the BeSD framework. RESULTS: The findings indicate regional disparities in herpes zoster vaccine uptake across Italy. Notably, the Islands region exhibits a particularly low vaccination rate (2.9%), highlighting the need for targeted interventions. The multivariate regression analysis showed that sociodemographic factors, limited access to healthcare services, and inadequate awareness of vaccine eligibility contribute to the lower uptake observed in this region. CONCLUSION: In conclusion, this research emphasizes regional disparities in herpes zoster (HZ) vaccination uptake in Italy. Demographic, socioeconomic, and geographic factors impact individuals' willingness to receive the vaccine. The study highlights the importance of awareness of vaccine eligibility and accessible vaccination facilities in increasing uptake rates.

Association between intravenous fluids during labor and primary postpartum hemorrhage: A retrospective cohort study.

INTRODUCTION: There is a major research gap relating to the impact of intravenous (IV) fluids administration during labor on maternal and neonatal outcomes. It is biologically plausible that a relationship between volume of IV fluids and primary postpartum hemorrhage (PPH) exists. The primary objective of this study was to evaluate whether the administration of high-volume IV fluids during labor (≥ 2500 mL) increases the risk of primary PPH and other adverse outcomes for women with a term, singleton pregnancy, in comparison to low-volume IV fluids during labor (<2500 mL). MATERIAL AND METHODS: A retrospective cohort study was conducted at a tertiary referral hospital in Sydney, Australia between 1st September 2021 and 31st October 2022. Inclusion criteria were: women with a live singleton fetus in a cephalic presentation; planning a vaginal birth; and admitted for labor and birth care between 37 and 42 week gestation. The study factor was IV fluids during labor and the primary outcome was primary PPH ≥500 mL. Secondary outcomes included cesarean section and major perineal injury. Pregnancy, birth, and postnatal data were obtained from the hospital's electronic clinical database, electronic medical records, and paper fluid order documentation. Multivariable logistic regression and multiple imputation were used to explore the relationship between volume of IV fluids in labor and PPH. RESULTS: A total of 1023 participants were included of which 339 had a primary PPH (33.1%). There was no association between high-volume IV fluids and PPH after adjusting for demographic and clinical factors (adjusted odds ratio [ORadj]1.02 95% confidence interval [95%CI] 0.72, 1.44). However, there was a positive association between high-volume IV fluids and cesarean section (ORadj 1.99; 95%CI 1.4, 2.8). CONCLUSIONS: The findings of this research are important to further knowledge relating to the administration of IV fluids during labor. The findings emphasize the importance of accurately documenting IV fluids administration and identifies research priorities to enable us to better understand the broader implications of IV fluids administration on pregnancy and perinatal outcomes.

The experience of traumatic events, psychological distress, and social support: links to COVID-19 vaccine hesitancy and trends with age in a group of older Australians.

BACKGROUND: Vaccination is important to reduce disease-associated morbidity and mortality in an ageing global population. While older adults are more likely than younger adults to accept vaccines, some remain hesitant. We sought to understand how traumatic events, psychological distress and social support contribute to older adults' intention to receive a COVID-19 vaccine and whether these experiences change with age. METHODS: We analysed survey data collected as part of the Sax Institute's 45 and Up Study in a population of Australian adults aged 60 years and over. Data were derived from the COVID Insights study; a series of supplementary surveys about how participants experienced the COVID-19 pandemic. RESULTS: Higher intention to receive a COVID-19 vaccine was associated with greater social support (adjusted odds ratio (aOR):1.08; 95%CI:1.06-1.11; p <.001) while lower intention was associated with personally experiencing a serious illness, injury or assault in the last 12 months (aOR:0.79; 95% CI:0.64-0.98; p =.03). Social support and the experience of traumatic events increased significantly with age, while psychological distress decreased. CONCLUSIONS: There may be factors beyond disease-associated risks that play a role in vaccine acceptance with age. Older Australians on the younger end of the age spectrum may have specific needs to address their hesitancy that may be overlooked.

Pneumococcal vaccine uptake among high-risk adults and children in Italy: results from the OBVIOUS project survey.

BACKGROUND: Streptococcus pneumoniae infections, including Invasive Pneumococcal Diseases (IPDs), pose a substantial public health challenge, causing significant morbidity and mortality, especially among children and older adults. Vaccination campaigns have played a vital role in reducing pneumococcal-related deaths. However, obstacles related to accessibility and awareness might impede optimal vaccine adoption. This study aims to provide comprehensive data on pneumococcal vaccine coverage and attitudes within at-risk groups in Italy, with the goal of informing public health strategies and addressing vaccination barriers. METHODS: Between April 11 and May 29, 2022, a questionnaire investigating vaccine uptake and attitudes toward several vaccinations was administered to 10,000 Italian adults, chosen through population-based sampling. Respondents who were targets of the campaign according to the 2017-2019 National Vaccination Plan, accessed questions regarding pneumococcal vaccination. Data on uptake, awareness of having the right to free vaccination, opinion on vaccine safety, concern with pneumococcal disease, and ease of access to vaccination services were summarized and presented based on statistical regions. Multinomial logistic regression analysis was used to explore factors influencing vaccine uptake. RESULTS: Out of 2357 eligible adult respondents (42.6% women; mean age: 58.1 ± 15.7), 39.5% received pneumococcal vaccination. Uptake differed among at-risk groups: respondents aged ≥65 (33.7%), with lung disease (48.4%), cardiovascular disease (46.6%), and diabetes (53.7%). Predictors of not being vaccinated and unwilling to included female gender, residing in rural areas, lower education, low concern about pneumococcal disease, vaccine safety concerns, and associations with vaccine-opposed acquaintances. Health access issues predicted willingness to be vaccinated despite non-vaccination. Pneumopathy, heart disease, diabetes, and living in Northeastern or Central Italy were linked to higher uptake. Among the 1064 parents of eligible children, uptake was 79.1%. Parental unawareness of children's free vaccination eligibility was a predictor of non-vaccination. Vaccine safety concerns correlated with reluctance to vaccinate children, while perceived healthcare access challenges were associated with wanting but not having received vaccination. CONCLUSIONS: Pneumococcal vaccination uptake within prioritized groups and children in Italy remains inadequate. Scarce awareness of vaccine availability and obstacles in accessing vaccinations emerge as principal barriers influencing this scenario.

Rates and determinants of Rotavirus vaccine uptake among children in Italy: a cross-sectional study within the 2022 OBVIOUS* project.

INTRODUCTION: The World Health Organization defines rotavirus as among the most severe causes of viral gastroenteritis affecting children under 5 year old. Italy and other European countries do not release disaggregated data on rotavirus vaccination coverage. This study aimed to assess the uptake and drivers of rotavirus vaccination in Italy. METHODS: We administered a survey to 10,000 Italian citizens recruited via an online panel and proportionate to key demographic strata. We examined rotavirus vaccine uptake among parents whose youngest child was aged 6 weeks to 4 years, their sociodemographic characteristics, their beliefs about vaccine administration, and who recommended the rotavirus vaccination. RESULTS: A total of 711 respondents met the inclusion criteria for the rotavirus vaccine questionnaire. The uptake was estimated at 60.3% nationwide (66.4% among mothers and 50.2% among fathers). Being a mother and living in cities/suburbs was significantly associated with a higher likelihood of vaccine uptake, while fathers were more likely to be uncertain of their children's vaccine status. Living in Central Italy and having friends/relatives opposed to vaccination were found to be significantly associated with a lower likelihood of vaccine uptake, while parents' education level and children's demographics were not found to correlate with any outcomes. In 90.3% of cases, the rotavirus vaccination was recalled as being recommended by a paediatrician. CONCLUSIONS: Consistent collection of behavioural preferences and socioeconomic characteristics of recipients of rotavirus vaccine campaigns, their epidemiological information, cost-benefit, and national policy data are crucial for designing effective vaccination strategies in Italy and other European countries with similar social profiles to reach the target uptake.

Evidence gaps and challenges in maintaining and increasing vaccine uptake: A Delphi survey with Australian stakeholders.

ISSUE ADDRESSED: Increasing and maintaining vaccination uptake is crucial for preventing and managing infectious diseases. In the context of the post-coronavirus disease 2019 (COVID-19) pandemic landscape, this paper examines the perceptions of immunisation implementers and policymakers to uncover the challenges and evidence gaps in routine immunisation efforts. METHODS: We conducted an online two-round modified Delphi survey with immunisation experts, senior public servants, policymakers, policy advisory groups, and representatives from peak bodies from across Australia. We asked respondents to outline what they see as the greatest challenges to increasing and maintaining uptake of recommended vaccines in Australia; the most difficult aspects of their work in vaccination; the largest evidence gaps in vaccine uptake; and the kinds of social and behavioural research they would like to see prioritised. RESULTS: The two most important challenges for increasing and maintaining vaccine uptake were effectively communicating the benefits of vaccines to parents and the public and ensuring accessible and affordable vaccination services. Participants strongly agreed that 'communication about the importance of vaccination' was the most difficult aspect of their work. Consistently important was the need to better engage specific population groups, such as culturally and linguistically diverse people, pregnant people, at risk cohorts, and health care providers. Social and behavioural research about 'how to effectively address hesitancy' was ranked highly among participants. CONCLUSIONS: Findings from this project help provide an understanding of the behavioural, social, ethical, and policy knowledge needs for immunisation policy and implementation in Australia. To respond to vaccine challenges, increase coverage and build public trust in vaccination, policymakers and governments should incorporate social research into vaccination programmes. SO WHAT?: Australia is preparing to launch a Centre for Disease Control. This study demonstrates the importance of integrating social, behavioural, ethical, and policy research into the fabric of this new enterprise. It underlines the need to capacity-build a workforce able to deliver high-quality research in these areas, address the needs of immunisation implementers and policymakers, and achieve good outcomes for Australians.

Vaccination barriers and drivers in Romania: a focused ethnographic study.

BACKGROUND: In 2016-18, a large measles outbreak occurred in Romania identified by pockets of sub-optimally vaccinated population groups in the country. The aim of the current study was to gain insight into barriers and drivers from the experience of measles vaccination from the perspectives of caregivers and their providers. METHODS: Data were collected by non-participant observation of vaccination consultations and individual interviews with health workers and caregivers in eight Romanian clinics with high or low measles vaccination uptake. Romanian stakeholders were involved in all steps of the study. The findings of this study were discussed during a workshop with key stakeholders. RESULTS: Over 400 h of observation and 161 interviews were conducted. A clear difference was found between clinics with high and low measles vaccination uptake which indicates that being aware of and following recommended practices for both vaccination service delivery and conveying vaccine recommendations to caregivers may have an impact on vaccine uptake. Barriers identified were related to shortcomings in following recommended practices for vaccination consultations by health workers (e.g. correctly assessing contraindications or providing enough information to allow an informed decision). These observations were largely confirmed in interviews with caregivers and revealed significant knowledge gaps. CONCLUSIONS: The identification of key barriers provided an opportunity to design specific interventions to improve vaccination service delivery (e.g. mobile vaccination clinics, use of an electronic vaccination registry system for scheduling of appointments) and build capacity among health workers (e.g. guidance and supporting materials and training programmes).

Association between traumatic life events and vaccine hesitancy: A cross-sectional Australian study.

OBJECTIVES: We sought to identify associations between the experience of traumatic life events and vaccination intention to inform whether trauma-affected individuals require targeted interventions when addressing vaccine hesitancy. STUDY DESIGN: We conducted an online cross-sectional survey to identify whether direct or indirect exposure to various traumatic life events and the presence of post-traumatic stress disorder (PTSD) symptoms are associated with willingness to receive a COVID-19 vaccine in an Australian sample. METHODS: A national online questionnaire was administered to a representative sample of 1050 Australian adults in September 2021. RESULTS: Lower willingness to receive a COVID-19 vaccine was associated with direct experience of a fire or explosion (adjusted odds ratio [aOR]: 0.42; 95% confidence interval [CI]: 0.23-0.78; P = 0.006), direct experience of severe human suffering (aOR:0.39; 95% CI: 0.21-0.71; P = 0.002) and screening positive for PTSD symptoms (aOR:0.52; 95% CI: 0.33-0.82; P = 0.005). Conversely, higher willingness to receive a COVID-19 vaccine was associated with indirect exposure to severe human suffering (aOR: 2.0; 95% CI: 1.21-3.22; P = 0.007). CONCLUSIONS: Our findings suggest that the experience of traumatic events and the presence of PTSD symptoms can contribute to vaccination decisions. Our work adds to the growing recognition of the need to effectively mediate the influence of traumatic experiences on encounters within the medical setting and supports the importance of addressing the needs of trauma-affected individuals in their vaccination experiences.

Midwives' perspectives of intravenous fluid management and fluid balance documentation in labour: A qualitative reflexive thematic analysis study.

AIM: To describe current practice, examine the influences and explore barriers and facilitators to accurate documentation, for the administration of intravenous fluids during labour. DESIGN: A descriptive qualitative study was performed. METHODS: Qualitative semi-structured interviews were conducted with Registered Midwives working across Australia. Midwives were recruited via email and social media advertisements. A maximum variation sampling strategy was used to identify potential participants. Interview questions explored four main areas: (i) understanding of indications for IV fluids in labour; (ii) identification of current practice; (iii) barriers to documentation and (iv) benefits and complications of IV fluid administration. Reflexive thematic analysis of recorded-transcribed interviews was conducted. RESULTS: Eleven midwives were interviewed. Clinical practice variation across Australia was recognized. Midwives reported a potential risk of harm for women and babies and a current lack of evidence, education and clinical guidance contributing to uncertainty around the use of IV fluids in labour. Overall, eight major themes were identified: (i) A variable clinical practice; (ii) Triggers and habits; (iii) Workplace and professional culture; (iv) Foundational knowledge; (v) Perception of risk; (vi) Professional standards and regulations; (vii) The importance of monitoring maternal fluid balance and (viii) barriers and facilitators to fluid balance documentation. CONCLUSION: There was widespread clinical variation identified and midwives reported a potential risk of harm. The major themes identified will inform future quantitative research examining the impact of IV fluids in labour. IMPACT: The implications of this research are important and potentially far-reaching. The administration of IV fluids to women in labour is a common clinical intervention. However, there is limited evidence available to guide practice. This study highlights the need for greater education and evidence examining maternal and neonatal outcomes to provide improved clinical guidance.

COVID-19 testing decisions and behaviours in two Australian cities.

ISSUE ADDRESSED: High levels of testing are crucial for minimising the spread of COVID-19. The aim of this study is to investigate what prevents people from getting a COVID-19 test when they are experiencing respiratory symptoms. METHODS: Semi-structured, qualitative interviews were conducted with 14 purposively sampled adults between 20 November 2020 and 3 March 2021 in two capital cities of Australia and analysed thematically. The analysis included people who reported having respiratory symptoms but who did not undergo a COVID-19 test. RESULTS: Participants appraised risks of having COVID-19, of infecting others or being infected whilst attending a testing site. They often weighed these appraisals against practical considerations of knowing where and how to get tested, inconvenience or financial loss. CONCLUSIONS: Clear public health messages communicating the importance of testing, even when symptoms are minor, may improve testing rates. Increasing the accessibility of testing centres, such as having them at transport hubs is important, as is providing adequate information about testing locations and queue lengths. SO WHAT?: The findings of our study suggest that more needs to be done to encourage people to get tested for COVID-19, especially when symptoms are minor. Clear communication about the importance of testing, along with easily accessible testing clinics, and financial support for those concerned about financial impacts may improve testing rates.

'Get your own house in order': Qualitative dialogue groups with nonvaccinating parents on how measles outbreaks in their community should be managed.

OBJECTIVE: Communities with high levels of vaccine rejection present unique challenges to vaccine-preventable disease outbreak management. We sought perspectives of nonvaccinating parents to inform public health responses in such communities. METHODS: Nineteen purposively sampled nonvaccinating Australian parents participated in one of seven online dialogue groups. We asked what they thought parents, school principals and public health professionals should do in a hypothetical school measles outbreak and used a framework approach to data analysis. RESULTS: Parents' views were grounded in strong beliefs in parental responsibility and the belief that vaccines are not effective, thus unvaccinated children do not therefore pose a threat. They then reasoned that the forced exclusion of unvaccinated children from school in a measles outbreak was disproportionate to the risk they pose, and their child's right to education should not be overridden. Nonvaccinating parents judged that all parents should keep sick children at home regardless of disease or vaccination status; that school principals should communicate directly with parents and avoid using social media; that public health professionals should provide information to parents so they can decide for themselves about excluding their children from school; that public health responses should avoid accidental identification of unvaccinated children and that mainstream media should be avoided as a communication tool. CONCLUSION: Nonvaccinating parents do not always agree with current Australian approaches to measles outbreak management. Their perspectives can inform approaches to outbreak responses in communities with high levels of vaccine rejection. PATIENT OR PUBLIC CONTRIBUTION: We sought input from individuals who did and did not vaccinate on study design in its early phases. Individual conversations were used deliberately as we felt the group advisory situation may have felt less safe for nonvaccinating parents, given the divisive and often hostile nature of the topic.

Examining Australian public perceptions and behaviors towards a future COVID-19 vaccine.

BACKGROUND: As immunisation program launches have previously demonstrated, it is essential that careful planning occurs now to ensure the readiness of the public for a COVID-19 vaccine. As part of that process, this study aimed to understand the public perceptions regarding a future COVID-19 vaccine in Australia. METHODS: A national cross-sectional online survey of 1420 Australian adults (18 years and older) was undertaken between 18 and 24 March 2020. The statistical analysis of the data included univariate and multivariable logistic regression model analysis. RESULTS: Respondents generally held positive views towards vaccination. Eighty percent (n = 1143) agreed with the statement that getting myself vaccinated for COVID-19 would be a good way to protect myself against infection. Females (n = 614, 83%) were more likely to agree with the statement than males (n = 529, 78%) (aOR = 1.4 (95% CI: 1.1-1.8); P = 0.03), while 91% of those aged 70 years and above agreed compared to 76% of 18-29-year-olds (aOR = 2.3 (95% CI:1.2-4.1); P = 0.008). Agreement was also higher for those with a self-reported chronic disease (aOR = 1.4 (95% CI: 1.1-2.0); P = 0.04) and among those who held private health insurance (aOR = 1.7 (95% CI: 1.3-2.3); P < 0.001). Beyond individual perceptions, 78% stated that their decision to vaccinate would be supported by family and friends. CONCLUSION: This study presents an early indication of public perceptions towards a future COVID-19 vaccine and represents a starting point for mapping vaccine perceptions. To support an effective launch of these new vaccines, governments need to use this time to understand the communities concerns and to identify the strategies that will support engagement.

Barriers to influenza vaccination of children hospitalised for acute respiratory illness: A cross-sectional survey.

AIM: To identify barriers to influenza vaccination of children hospitalised for acute respiratory illness in Australia. METHODS: A total of 595 parents of children hospitalised with acute respiratory illness across five tertiary hospitals in 2019 participated in an online survey. Multivariate logistic regression identified factors most strongly associated with influenza vaccination barriers. RESULTS: Odds of influenza vaccination were lower with lack of health-care provider (HCP) recommendation (adjusted odds ratio (aOR) 0.18; 95% confidence interval (CI): 0.08-0.38); if parents had difficulties (aOR 0.19; 95% CI: 0.08-0.47) or were 'neutral' (aOR 0.23; 95% CI: 0.06-0.82) in remembering to make an appointment; and if parents had difficulties (aOR 0.21; 95% CI: 0.07-0.62) or were 'neutral' (aOR 0.24; 95% CI: 0.07-0.79) regarding getting an appointment for vaccination. Odds were also lower if parents did not believe (aOR 0.27; 95% CI: 0.08-0.90) or were 'neutral' (aOR 0.15; 95% CI: 0.04-0.49) regarding whether the people most important to them would have their child/ren vaccinated against influenza. Children had lower odds of vaccination if parents did not support (aOR 0.09; 95% CI: 0.01-0.82) or were ambivalent (aOR 0.09; 95% CI: 0.01-0.56) in their support for influenza vaccination. Finally, lack of history of influenza vaccination of child (aOR 0.38; 95% CI: 0.18-0.81) and respondent (aOR 0.25; 95% CI: 0.11-0.56) were associated with lack of receipt of influenza vaccine before admission for acute respiratory infection. CONCLUSIONS: Assisting parents in remembering and accessing influenza vaccination and encouraging health-care providers to recommend vaccination may increase uptake.

COVID-19 Misinformation Trends in Australia: Prospective Longitudinal National Survey.

BACKGROUND: Misinformation about COVID-19 is common and has been spreading rapidly across the globe through social media platforms and other information systems. Understanding what the public knows about COVID-19 and identifying beliefs based on misinformation can help shape effective public health communications to ensure efforts to reduce viral transmission are not undermined. OBJECTIVE: This study aimed to investigate the prevalence and factors associated with COVID-19 misinformation in Australia and their changes over time. METHODS: This prospective, longitudinal national survey was completed by adults (18 years and above) across April (n=4362), May (n=1882), and June (n=1369) 2020. RESULTS: Stronger agreement with misinformation was associated with younger age, male gender, lower education level, and language other than English spoken at home (P<.01 for all). After controlling for these variables, misinformation beliefs were significantly associated (P<.001) with lower levels of digital health literacy, perceived threat of COVID-19, confidence in government, and trust in scientific institutions. Analyses of specific government-identified misinformation revealed 3 clusters: prevention (associated with male gender and younger age), causation (associated with lower education level and greater social disadvantage), and cure (associated with younger age). Lower institutional trust and greater rejection of official government accounts were associated with stronger agreement with COVID-19 misinformation. CONCLUSIONS: The findings of this study highlight important gaps in communication effectiveness, which must be addressed to ensure effective COVID-19 prevention.

Designing a multi-component intervention (P3-MumBubVax) to promote vaccination in antenatal care in Australia.

ISSUE ADDRESSED: Coverage of maternal influenza and pertussis vaccines remains suboptimal in Australia, and pockets of low childhood vaccine coverage persist nationwide. Maternal vaccine uptake is estimated to be between 35% and 60% for influenza vaccination and between 65% and 80% for pertussis vaccination. Australian midwives are highly trusted and ideally placed to discuss vaccines with expectant parents, but there are no evidence-based interventions to optimise these discussions and promote maternal and childhood vaccine acceptance in the Australian public antenatal setting. METHODS: We gathered qualitative data from Australian midwives, reviewed theoretical models, and adapted existing vaccine communication tools to develop the multi-component P3-MumBubVax intervention. Through 12 interviews at two Australian hospitals, we explored midwives' vaccination attitudes and values, perceived role in vaccine advocacy and delivery, and barriers and enablers to intervention implementation. Applying the theory-based P3 intervention model, we designed intervention components targeting the Practice, Provider and Parent levels. Midwives provided feedback on prototype intervention features through two focus groups. RESULTS: The P3-MumBubVax intervention includes practice-level prompts and identification of a vaccine champion. Provider-level components are a vaccine communication training module, learning exercise, and website with printable fact sheets. Parent-level intervention components include text message reminders to receive influenza and pertussis vaccines in pregnancy, as well as online information on vaccine safety, effectiveness and disease severity. CONCLUSIONS: The P3-MumBubVax intervention is the first Australian antenatal intervention designed to support both maternal and childhood vaccine uptake. A pilot study is underway to inform a planned cluster randomised controlled trial. SO WHAT?: Barriers to vaccine acceptance and uptake are complex. The P3 model is a promising evidence-informed multi-component intervention strategy targeting all three levels influencing health care decision-making.

Limited Role of Bots in Spreading Vaccine-Critical Information Among Active Twitter Users in the United States: 2017-2019.

Objectives. To examine the role that bots play in spreading vaccine information on Twitter by measuring exposure and engagement among active users from the United States.Methods. We sampled 53 188 US Twitter users and examined who they follow and retweet across 21 million vaccine-related tweets (January 12, 2017-December 3, 2019). Our analyses compared bots to human-operated accounts and vaccine-critical tweets to other vaccine-related tweets.Results. The median number of potential exposures to vaccine-related tweets per user was 757 (interquartile range [IQR] = 168-4435), of which 27 (IQR = 6-169) were vaccine critical, and 0 (IQR = 0-12) originated from bots. We found that 36.7% of users retweeted vaccine-related content, 4.5% retweeted vaccine-critical content, and 2.1% retweeted vaccine content from bots. Compared with other users, the 5.8% for whom vaccine-critical tweets made up most exposures more often retweeted vaccine content (62.9%; odds ratio [OR] = 2.9; 95% confidence interval [CI] = 2.7, 3.1), vaccine-critical content (35.0%; OR = 19.0; 95% CI = 17.3, 20.9), and bots (8.8%; OR = 5.4; 95% CI = 4.7, 6.3).Conclusions. A small proportion of vaccine-critical information that reaches active US Twitter users comes from bots.

A systematic review of studies that measure parental vaccine attitudes and beliefs in childhood vaccination.

BACKGROUND: Acceptance of vaccines is an important predictor of vaccine uptake. This has public health implications as those who are not vaccinated are at a higher risk of infection from vaccine preventable diseases. We aimed to examine how parental attitudes and beliefs towards childhood vaccination were measured in questionnaires through a systematic review of the literature. METHODS: We systematically reviewed the literature to identify primary research studies using tools to measure vaccine attitudes and beliefs, published between January 2012 and May 2018. Studies were included if they involved a quantitative survey of the attitudes and beliefs of parents about vaccinations recommended for children. We undertook a synthesis of the results with a focus on evaluating the tools used to measure hesitancy. RESULTS: A total of 116 studies met the inclusion criteria, 99 used a cross sectional study design, 5 used a case control study design, 4 used a pre-post study design and 8 used mixed methods study designs. Sample sizes of included studies ranged from 49 to 12,259. The most commonly used tool was the Parent Attitudes about Childhood Vaccines (PACV) Survey (n = 7). The most common theoretical framework used was the Health Belief Model (n = 25). Questions eliciting vaccination attitudes and beliefs varied widely. CONCLUSIONS: There was heterogeneity in the types of questionnaires used in studies investigating attitudes and beliefs about vaccination in parents. Methods to measure parental attitudes and beliefs about vaccination could be improved with validated and standardised yet flexible instruments. The use of a standard set of questions should be encouraged in this area of study.

A Web Application About Herd Immunity Using Personalized Avatars: Development Study.

BACKGROUND: Herd immunity or community immunity refers to the reduced risk of infection among susceptible individuals in a population through the presence and proximity of immune individuals. Recent studies suggest that improving the understanding of community immunity may increase intentions to get vaccinated. OBJECTIVE: This study aims to design a web application about community immunity and optimize it based on users' cognitive and emotional responses. METHODS: Our multidisciplinary team developed a web application about community immunity to communicate epidemiological evidence in a personalized way. In our application, people build their own community by creating an avatar representing themselves and 8 other avatars representing people around them, for example, their family or coworkers. The application integrates these avatars in a 2-min visualization showing how different parameters (eg, vaccine coverage, and contact within communities) influence community immunity. We predefined communication goals, created prototype visualizations, and tested four iterative versions of our visualization in a university-based human-computer interaction laboratory and community-based settings (a cafeteria, two shopping malls, and a public library). Data included psychophysiological measures (eye tracking, galvanic skin response, facial emotion recognition, and electroencephalogram) to assess participants' cognitive and affective responses to the visualization and verbal feedback to assess their interpretations of the visualization's content and messaging. RESULTS: Among 110 participants across all four cycles, 68 (61.8%) were women and 38 (34.5%) were men (4/110, 3.6%; not reported), with a mean age of 38 (SD 17) years. More than half (65/110, 59.0%) of participants reported having a university-level education. Iterative changes across the cycles included adding the ability for users to create their own avatars, specific signals about who was represented by the different avatars, using color and movement to indicate protection or lack of protection from infectious disease, and changes to terminology to ensure clarity for people with varying educational backgrounds. Overall, we observed 3 generalizable findings. First, visualization does indeed appear to be a promising medium for conveying what community immunity is and how it works. Second, by involving multiple users in an iterative design process, it is possible to create a short and simple visualization that clearly conveys a complex topic. Finally, evaluating users' emotional responses during the design process, in addition to their cognitive responses, offers insights that help inform the final design of an intervention. CONCLUSIONS: Visualization with personalized avatars may help people understand their individual roles in population health. Our app showed promise as a method of communicating the relationship between individual behavior and community health. The next steps will include assessing the effects of the application on risk perception, knowledge, and vaccination intentions in a randomized controlled trial. This study offers a potential road map for designing health communication materials for complex topics such as community immunity.