Immunization: vital progress, unfinished agenda.

Vaccination against infectious diseases has changed the future of the human species, saving millions of lives every year, both children and adults, and providing major benefits to society as a whole. Here we show, however, that national and sub-national coverage of vaccination varies greatly and major unmet needs persist. Although scientific progress opens exciting perspectives in terms of new vaccines, the pathway from discovery to sustainable implementation can be long and difficult, from the financing, development and licensing to programme implementation and public acceptance. Immunization is one of the best investments in health and should remain a priority for research, industry, public health and society.

Spatiotemporal trends in COVID-19 vaccine sentiments on a social media platform and correlations with reported vaccine coverage.

Objective: To assess spatiotemporal trends in, and determinants of, the acceptance of coronavirus disease 2019 (COVID-19) vaccination globally, as expressed on the social media platform X (formerly Twitter). Methods: We collected over 13 million posts on the platform regarding COVID-19 vaccination made between November 2020 and March 2022 in 90 languages. Multilingual deep learning XLM-RoBERTa models annotated all posts using an annotation framework after being fine-tuned on 8125 manually annotated, English-language posts. The annotation results were used to assess spatiotemporal trends in COVID-19 vaccine acceptance and confidence as expressed by platform users in 135 countries and territories. We identified associations between spatiotemporal trends in vaccine acceptance and country-level characteristics and public policies by using univariate and multivariate regression analysis. Findings: A greater proportion of platform users in the World Health Organization's South-East Asia, Eastern Mediterranean and Western Pacific Regions expressed vaccine acceptance than users in the rest of the world. Countries in which a greater proportion of platform users expressed vaccine acceptance had higher COVID-19 vaccine coverage rates. Trust in government was also associated with greater vaccine acceptance. Internationally, vaccine acceptance and confidence declined among platform users as: (i) vaccination eligibility was extended to adolescents; (ii) vaccine supplies became sufficient; (iii) nonpharmaceutical interventions were relaxed; and (iv) global reports on adverse events following vaccination appeared. Conclusion: Social media listening could provide an effective and expeditious means of informing public health policies during pandemics, and could supplement existing public health surveillance approaches in addressing global health issues.

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.

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.

Between now and later: a mixed methods study of HPV vaccination delay among Chinese caregivers in urban Chengdu, China.

BACKGROUND: Adolescent girls in China have a low HPV vaccination rate. Although vaccination is recommended by the Chinese health authorities, the cost is not covered by the national immunisation programme. Vaccination delay, among other reasons such as supply shortage and poor affordability, may contribute to low uptake. This sequential mixed methods study aimed to identify potential factors of delayed HPV vaccination among Chinese adolescent girls. METHODS: Quantitative data about the attitudes and perceptions of HPV vaccination were collected from 100 caregivers of 14-18-year-old girls using an online survey in Chengdu, China. The survey data informed a subsequent qualitative study using four focus group discussions. We conducted a descriptive analysis of the survey data and a thematic analysis of the qualitative data. The findings were interpreted using a health behaviour model adapted from the Health Belief Model and the Andersen's Behavioural Model for Health Services Use. RESULTS: A total of 100 caregivers - 85 were mothers and 15 were fathers - participated in the survey; 21 caregivers joined focus group discussions. When asked about their intended course of action if the 9vHPV vaccine was out-of-stock, 74% chose to delay until the 9vHPV vaccine is available while 26% would consider 2vHPV or 4vHPV vaccines or seek alternative ways to procure the vaccine. Qualitative results confirmed that caregivers preferred delaying HPV vaccination for adolescent girls. The intent to delay was influenced by systemic barriers such as supply shortage and individual-level factors such as a preference for the 9vHPV vaccine, safety concerns, inadequate health communication, and the belief that adolescents were unlikely to be sexually active. CONCLUSION: In urban areas, Chinese caregivers' intent to delay vaccination in favour of 9vHPV vaccine over receiving the more accessible options was influenced by a mix of individual and contextual factors. Focussed health communication strategies are needed to accelerate HPV vaccination among adolescents.

Influenza vaccine uptake among children and older adults in China: a secondary analysis of a quasi-experimental study.

BACKGROUND: Influenza vaccination is the key to prevent influenza-related disease, especially among high-risk populations. However, influenza vaccine uptake in China is low. This secondary analysis of a quasi-experimental trial aimed to understand factors associated with influenza vaccine uptake among children and older people stratified by funding context. METHODS: A total of 225 children (aged 0.5-8 years) and 225 older people (aged 60 years or above) were recruited from three clinics (rural, suburban and urban) in Guangdong Province. Participants were allocated into two groups based on funding contexts: a self-paid group (N = 150, 75 children and 75 older adults) in which participants paid full price for their vaccination; and a subsidized group (N = 300, 150 children and 150 older adults) in which varying levels of financial support was provided. Univariate and multivariable logistic regressions were conducted stratified by funding contexts. RESULTS: Overall, 75.0% (225/300) of participants in the subsidized group and 36.7% (55/150) in the self-paid group got vaccinated. Older adults had lower vaccination rates than children in both funding groups, while both age groups showed much higher uptake in the subsidized group than in the self-paid group (aOR = 5.96, 95% CI: 3.77-9.42, p = 0.001). In the self-paid group, having prior influenza vaccination history of children (aOR:2.61, 95%CI: 1.06-6.42) or older people (aOR:4.76, 95%CI: 1.08-20.90) was associated with increased influenza vaccine uptake compared to those who had no prior vaccination experiences in the family. While in the subsidized group, participants who got married or lived with partners (aOR = 0.32, 0.10-0.98) had lower vaccination uptake than single ones. Trust in providers' advice (aOR = 4.95, 95%CI:1.99, 12.43), perceived effectiveness of the vaccine (aOR: 12.18, 95%CI: 5.21-28.50), and experienced influenza-like illnesses in the family in the past year (aOR = 46.52, 4.10, 533.78) were associated with higher vaccine uptake. CONCLUSIONS: Older people had suboptimal vaccine uptake compared to children in both contexts and need more attention to enhance influenza vaccination. Tailoring interventions to different vaccine funding contexts may help improve influenza vaccination: In self-paid context, motivating people to accept their first ever influenza vaccination may be a promising strategy. In subsidized context, improving public confidence in vaccine effectiveness and providers' advice would be useful.

"Figuring stuff out myself" - a qualitative study on maternal vaccination in socially and ethnically diverse areas in England.

BACKGROUND: Maternal vaccinations against Influenza, Pertussis, and Covid-19 are recommended in the UK, and vaccines against further infections may become available soon. However, many pregnant women, especially in socially and ethnically diverse areas, have low vaccine uptake. Qualitative studies on the reasons and possible solutions are needed that are inclusive of disadvantaged and minority ethnic groups. We therefore aimed to understand the complex interplay between structural and behavioural factors contributing to the low maternal vaccine uptake in socially and ethnically diverse areas in London in the Covid-19 context. METHODS: In 2022, we conducted semi-structured interviews and a focus group discussion among a purposive sample of 38 pregnant/recently pregnant women and 20 health service providers, including 12 midwives. Participants were recruited in ethnically diverse London boroughs. We followed a critical realist paradigm and used a thematic analysis approach. RESULTS: The sample included participants who took all, some or none of the maternal vaccines, with some participants unsure whether they had taken or been offered the vaccines. Decision-making was passive or active, with the expectation for pregnant women to do their 'own research'. Participants described various individual, social and contextual influences on their decision-making as they navigated the antenatal care system. Missing or conflicting information from providers meant knowledge gaps were sometimes filled with misinformation from unreliable sources that increased uncertainties and mistrust. Both pregnant women and providers described structural and organisational factors that hindered access to information and vaccinations, including lack of training, time and resources, and shortcomings of health information systems and apps. Some participants described factors that facilitated vaccination uptake and many made recommendations for improvements. CONCLUSIONS: Our study showed how structural and organisational factors can compound uncertainties around maternal vaccination among socially and ethnically diverse populations. Results highlight the need for more reliable resources, streamlined workflows, improved electronic information systems and training in their use. Roles and responsibilities should be clarified with potential greater involvement of nurses and pharmacists in vaccine provision. Education and communication should consider individual (language/digital) skills and needs for information and reassurance. Further research is needed to co-produce solutions with service users and providers.

Conversational AI and Vaccine Communication: Systematic Review of the Evidence.

BACKGROUND: Since the mid-2010s, use of conversational artificial intelligence (AI; chatbots) in health care has expanded significantly, especially in the context of increased burdens on health systems and restrictions on in-person consultations with health care providers during the COVID-19 pandemic. One emerging use for conversational AI is to capture evolving questions and communicate information about vaccines and vaccination. OBJECTIVE: The objective of this systematic review was to examine documented uses and evidence on the effectiveness of conversational AI for vaccine communication. METHODS: This systematic review was conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. PubMed, Web of Science, PsycINFO, MEDLINE, Scopus, CINAHL Complete, Cochrane Library, Embase, Epistemonikos, Global Health, Global Index Medicus, Academic Search Complete, and the University of London library database were searched for papers on the use of conversational AI for vaccine communication. The inclusion criteria were studies that included (1) documented instances of conversational AI being used for the purpose of vaccine communication and (2) evaluation data on the impact and effectiveness of the intervention. RESULTS: After duplicates were removed, the review identified 496 unique records, which were then screened by title and abstract, of which 38 were identified for full-text review. Seven fit the inclusion criteria and were assessed and summarized in the findings of this review. Overall, vaccine chatbots deployed to date have been relatively simple in their design and have mainly been used to provide factual information to users in response to their questions about vaccines. Additionally, chatbots have been used for vaccination scheduling, appointment reminders, debunking misinformation, and, in some cases, for vaccine counseling and persuasion. Available evidence suggests that chatbots can have a positive effect on vaccine attitudes; however, studies were typically exploratory in nature, and some lacked a control group or had very small sample sizes. CONCLUSIONS: The review found evidence of potential benefits from conversational AI for vaccine communication. Factors that may contribute to the effectiveness of vaccine chatbots include their ability to provide credible and personalized information in real time, the familiarity and accessibility of the chatbot platform, and the extent to which interactions with the chatbot feel "natural" to users. However, evaluations have focused on the short-term, direct effects of chatbots on their users. The potential longer-term and societal impacts of conversational AI have yet to be analyzed. In addition, existing studies do not adequately address how ethics apply in the field of conversational AI around vaccines. In a context where further digitalization of vaccine communication can be anticipated, additional high-quality research will be required across all these areas.

Challenges in ensuring global access to COVID-19 vaccines: production, affordability, allocation, and deployment.

The COVID-19 pandemic is unlikely to end until there is global roll-out of vaccines that protect against severe disease and preferably drive herd immunity. Regulators in numerous countries have authorised or approved COVID-19 vaccines for human use, with more expected to be licensed in 2021. Yet having licensed vaccines is not enough to achieve global control of COVID-19: they also need to be produced at scale, priced affordably, allocated globally so that they are available where needed, and widely deployed in local communities. In this Health Policy paper, we review potential challenges to success in each of these dimensions and discuss policy implications. To guide our review, we developed a dashboard to highlight key characteristics of 26 leading vaccine candidates, including efficacy levels, dosing regimens, storage requirements, prices, production capacities in 2021, and stocks reserved for low-income and middle-income countries. We use a traffic-light system to signal the potential contributions of each candidate to achieving global vaccine immunity, highlighting important trade-offs that policy makers need to consider when developing and implementing vaccination programmes. Although specific datapoints are subject to change as the pandemic response progresses, the dashboard will continue to provide a useful lens through which to analyse the key issues affecting the use of COVID-19 vaccines. We also present original data from a 32-country survey (n=26 758) on potential acceptance of COVID-19 vaccines, conducted from October to December, 2020. Vaccine acceptance was highest in Vietnam (98%), India (91%), China (91%), Denmark (87%), and South Korea (87%), and lowest in Serbia (38%), Croatia (41%), France (44%), Lebanon (44%), and Paraguay (51%).

Childhood COVID-19 vaccine acceptance and preference from caregivers and healthcare workers in China: A survey experiment.

With approval of more COVID-19 vaccines for children, vaccine attributes may influence parental acceptance and choices. We aimed to assess effects of vaccine attributes and information on herd immunity on childhood COVID-19 vaccine acceptance. A survey experiment was conducted with caregivers of children aged 6 months to 11 years old and health care workers (HCWs) in China from September 14 to November 18, 2021. Respondents were randomly assigned to receive differing information on herd immunity (> 80% of the entire population must be vaccinated; or no information). Respondents then completed eight discrete choice tasks to assess vaccine acceptance based on attributes. 2331 (90.07%) of 2588 surveyed caregivers and 1576 (92.71%) of 1700 surveyed HCWs would accept COVID-19 vaccination for children, respectively. High Odds Ratios (OR) were found for acceptance of a vaccine with 90% over 50% efficacy (OR 6.70 [95% CI 6.11-7.35] for caregivers; 11.44 [10.12-12.95] for HCWs); and risk of adverse reactions to be 1 over 10 in 10,000 (3.96 [3.72-4.22] for caregivers; 2.98 [2.76-3.22] for HCWs). To achieve herd immunity target (> 80% vaccination coverage), vaccine efficacy should reach over 70% and risk of adverse reactions lower than 1 in 10,000. Knowledge on herd immunity target increased the odds of vaccine acceptance (1.82 [1.34-2.46] for caregivers; 2.42 [1.58-3.72] for HCWs). Childhood COVID-19 vaccine acceptance was high in China, independent of child's age, and depended on vaccine attributes.

Vaccines and the social amplification of risk.

In 2019, the World Health Organization (WHO) named "Vaccine Hesitancy" one of the top 10 threats to global health. Shortly afterward, the COVID-19 pandemic emerged as the world's predominant health concern. COVID-19 vaccines of several types have been developed, tested, and partially deployed with remarkable speed; vaccines are now the primary control measure and hope for a return to normalcy. However, hesitancy concerning these vaccines, along with resistance to masking and other control measures, remains a substantial obstacle. The previous waves of vaccine hesitancy that led to the WHO threat designation, together with recent COVID-19 experience, provide a window for viewing new forms of social amplification of risk (SAR). Not surprisingly, vaccines provide fertile ground for questions, anxieties, concerns, and rumors. These appear in new globalized hyperconnected communications landscapes and in the context of complex human (social, economic, and political) systems that exhibit evolving concerns about vaccines and authorities. We look at drivers, impacts, and implications for vaccine initiatives in several recent historical examples and in the current efforts with COVID-19 vaccination. Findings and insights were drawn from the Vaccine Confidence Project's decade long monitoring of media and social media and its related research efforts. The trends in vaccine confidence and resistance have implications for updating the social amplification of risk framework (SARF); in turn, SARF has practical implications for guiding efforts to alleviate vaccine hesitancy and to mitigate harms from intentional and unintentional vaccine scares.

Mapping global trends in vaccine confidence and investigating barriers to vaccine uptake: a large-scale retrospective temporal modelling study.

BACKGROUND: There is growing evidence of vaccine delays or refusals due to a lack of trust in the importance, safety, or effectiveness of vaccines, alongside persisting access issues. Although immunisation coverage is reported administratively across the world, no similarly robust monitoring system exists for vaccine confidence. In this study, vaccine confidence was mapped across 149 countries between 2015 and 2019. METHODS: In this large-scale retrospective data-driven analysis, we examined global trends in vaccine confidence using data from 290 surveys done between September, 2015, and December, 2019, across 149 countries, and including 284 381 individuals. We used a Bayesian multinomial logit Gaussian process model to produce estimates of public perceptions towards the safety, importance, and effectiveness of vaccines. Associations between vaccine uptake and a large range of putative drivers of uptake, including vaccine confidence, socioeconomic status, and sources of trust, were determined using univariate Bayesian logistic regressions. Gibbs sampling was used for Bayesian model inference, with 95% Bayesian highest posterior density intervals used to capture uncertainty. FINDINGS: Between November, 2015, and December, 2019, we estimate that confidence in the importance, safety, and effectiveness of vaccines fell in Afghanistan, Indonesia, Pakistan, the Philippines, and South Korea. We found significant increases in respondents strongly disagreeing that vaccines are safe between 2015 and 2019 in six countries: Afghanistan, Azerbaijan, Indonesia, Nigeria, Pakistan, and Serbia. We find signs that confidence has improved between 2018 and 2019 in some EU member states, including Finland, France, Ireland, and Italy, with recent losses detected in Poland. Confidence in the importance of vaccines (rather than in their safety or effectiveness) had the strongest univariate association with vaccine uptake compared with other determinants considered. When a link was found between individuals' religious beliefs and uptake, findings indicated that minority religious groups tended to have lower probabilities of uptake. INTERPRETATION: To our knowledge, this is the largest study of global vaccine confidence to date, allowing for cross-country comparisons and changes over time. Our findings highlight the importance of regular monitoring to detect emerging trends to prompt interventions to build and sustain vaccine confidence. FUNDING: European Commission, Wellcome, and Engineering and Physical Sciences Research Council.

Use of Data to Understand the Social Determinants of Depression in Two Middle-Income Countries: the 3-D Commission.

Depression accounts for a large share of the global disease burden, with an estimated 264 million people globally suffering from depression. Despite being one of the most common kinds of mental health (MH) disorders, much about depression remains unknown. There are limited data about depression, in terms of its occurrence, distribution, and wider social determinants. This work examined the use of novel data sources for assessing the scope and social determinants of depression, with a view to informing the reduction of the global burden of depression.This study focused on new and traditional sources of data on depression and its social determinants in two middle-income countries (LMICs), namely, Brazil and India. We identified data sources using a combination of a targeted PubMed search, Google search, expert consultations, and snowball sampling of the relevant literature published between October 2010 and September 2020. Our search focused on data sources on the following HEALTHY subset of determinants: healthcare (H), education (E), access to healthy choices (A), labor/employment (L), transportation (T), housing (H), and income (Y).Despite the emergence of a variety of data sources, their use in the study of depression and its HEALTHY determinants in India and Brazil are still limited. Survey-based data are still the most widely used source. In instances where new data sources are used, the most commonly used data sources include social media (twitter data in particular), geographic information systems/global positioning systems (GIS/GPS), mobile phone, and satellite imagery. Often, the new data sources are used in conjunction with traditional sources of data. In Brazil, the limited use of new data sources to study depression and its HEALTHY determinants may be linked to (a) the government's outsized role in coordinating healthcare delivery and controlling the data system, thus limiting innovation that may be expected from the private sector; (b) the government routinely collecting data on depression and other MH disorders (and therefore, does not see the need for other data sources); and (c) insufficient prioritization of MH as a whole. In India, the limited use of new data sources to study depression and its HEALTHY determinants could be a function of (a) the lack of appropriate regulation and incentives to encourage data sharing by and within the private sector, (b) absence of purposeful data collection at subnational levels, and (c) inadequate prioritization of MH. There is a continuing gap in the collection and analysis of data on depression, possibly reflecting the limited priority accorded to mental health as a whole. The relatively limited use of data to inform our understanding of the HEALTHY determinants of depression suggests a substantial need for support of independent research using new data sources. Finally, there is a need to revisit the universal health coverage (UHC) frameworks, as these frameworks currently do not include depression and other mental health-related indicators so as to enable tracking of progress (or lack thereof) on such indicators.

Data Sources for Understanding the Social Determinants of Health: Examples from Two Middle-Income Countries: the 3-D Commission.

The expansion in the scope, scale, and sources of data on the wider social determinants of health (SDH) in the last decades could bridge gaps in information available for decision-making. However, challenges remain in making data widely available, accessible, and useful towards improving population health. While traditional, government-supported data sources and comparable data are most often used to characterize social determinants, there are still capacity and management constraints on data availability and use. Conversely, privately held data may not be shared. This study reviews and discusses the nature, sources, and uses of data on SDH, with illustrations from two middle-income countries: Kenya and the Philippines. The review highlights opportunities presented by new data sources, including the use of big data technologies, to capture data on social determinants that can be useful to inform population health. We conducted a search between October 2010 and September 2020 for grey and scientific publications on social determinants using a search strategy in PubMed and a manual snowball search. We assessed data sources and the data environment in both Kenya and the Philippines. We found limited evidence of the use of new sources of data to study the wider SDH, as most of the studies available used traditional sources. There was also no evidence of qualitative big data being used. Kenya has more publications using new data sources, except on the labor determinant, than the Philippines. The Philippines has a more consistent distribution of the use of new data sources across the HEALTHY determinants than Kenya, where there is greater variation of the number of publications across determinants. The results suggest that both countries use limited SDH data from new data sources. This limited use could be due to a number of factors including the absence of standardized indicators of SDH, inadequate trust and acceptability of data collection methods, and limited infrastructure to pool, analyze, and translate data.

"Saint Google, now we have information!": a qualitative study on narratives of trust and attitudes towards maternal vaccination in Mexico City and Toluca.

BACKGROUND: Maternal vaccination is key to decreasing maternal and infant mortality globally. Yet perceptions about maternal vaccines and immunization among pregnant women are often understudied, particularly in low- and middle- income countries. This qualitative study explored trust, views, and attitudes towards maternal immunization among pregnant women in Mexico. A total of 54 women from Mexico City and Toluca participated in the in-depth interviews and focus groups. We explored participants' experiences with maternal vaccination, as well as how they navigated the health system, searched for information, and made decisions around maternal immunization. RESULTS: Our findings point to issues around access and quality of maternal healthcare, including immunizations services. While healthcare professionals were recognized for their expertise, participants reported not receiving enough information to make informed decisions and used online search engines and digital media to obtain more information about maternal healthcare. Some participants held strong doubts over the benefits of vaccination and were hesitant about the safety and efficacy of maternal vaccines. These concerns were also shared by pregnant women who had been vaccinated. Some participants disclosed low levels of trust in government and vaccination campaigns. CONCLUSION: Pregnant women, soon to be parents and making vaccination decisions for their child, constitute an important target group for policymakers seeking optimal maternal as well as childhood immunization coverage. Our findings highlight the importance of targeted communication, trust-building and engagement strategies to strengthen confidence in immunization amongst this group.

Assessing COVID-19 Vaccine Hesitancy, Confidence, and Public Engagement: A Global Social Listening Study.

BACKGROUND: Monitoring public confidence and hesitancy is crucial for the COVID-19 vaccine rollout. Social media listening (infoveillance) can not only monitor public attitudes on COVID-19 vaccines but also assess the dissemination of and public engagement with these opinions. OBJECTIVE: This study aims to assess global hesitancy, confidence, and public engagement toward COVID-19 vaccination. METHODS: We collected posts mentioning the COVID-19 vaccine between June and July 2020 on Twitter from New York (United States), London (United Kingdom), Mumbai (India), and Sao Paulo (Brazil), and Sina Weibo posts from Beijing (China). In total, we manually coded 12,886 posts from the five global metropolises with high COVID-19 burdens, and after assessment, 7032 posts were included in the analysis. We manually double-coded these posts using a coding framework developed according to the World Health Organization's Confidence, Complacency, and Convenience model of vaccine hesitancy, and conducted engagement analysis to investigate public communication about COVID-19 vaccines on social media. RESULTS: Among social media users, 36.4% (571/1568) in New York, 51.3% (738/1440) in London, 67.3% (144/214) in Sao Paulo, 69.8% (726/1040) in Mumbai, and 76.8% (2128/2770) in Beijing indicated that they intended to accept a COVID-19 vaccination. With a high perceived risk of getting COVID-19, more tweeters in New York and London expressed a lack of confidence in vaccine safety, distrust in governments and experts, and widespread misinformation or rumors. Tweeters from Mumbai, Sao Paulo, and Beijing worried more about vaccine production and supply, whereas tweeters from New York and London had more concerns about vaccine distribution and inequity. Negative tweets expressing lack of vaccine confidence and misinformation or rumors had more followers and attracted more public engagement online. CONCLUSIONS: COVID-19 vaccine hesitancy is prevalent worldwide, and negative tweets attract higher engagement on social media. It is urgent to develop an effective vaccine campaign that boosts public confidence and addresses hesitancy for COVID-19 vaccine rollouts.