Vaccine hesitancy: evidence from an adverse events following immunization database, and the role of cognitive biases

Knowledge, attitude, and practice toward herpes zoster (HZ) and HZ vaccination: Concept elicitation findings from a multi-country study in the Asia Pacific

Herpes zoster (HZ) is a prevalent disease characterized by a painful rash. A multi‑country study was conducted to elicit public and physician knowledge, attitude, and practice (KAP) toward HZ disease and vaccination for the assessment of local factors influencing HZ vaccine perceptions in four Asian-Pacific countries/territories One-to-one qualitative interviews were conducted in 2022, among the public (people aged ≥ 50 years, adults with parents aged ≥ 50 years, zoster vaccine live-vaccinated individuals aged ≥ 50 years in Republic of Korea, and HZ patients; n = 78) and physicians (general practitioners and specialists; n = 24). Themes surrounding KAP toward HZ and HZ vaccination were summarized using a thematic analysis. A substantial knowledge gap related to HZ was observed among the public, including its causes, long-term impacts, and the at-risk population. There was a low perceived risk of HZ and low general awareness of HZ vaccine availability, although country/territory-specific differences existed. Fear of HZ-associated pain contributed toward vaccination intent among HZ patients and adults with parents aged ≥ 50 years. HZ-naïve adults who were encouraged to receive the vaccine by others were not motivated to do so due to optimism bias. Physicians were perceived to be a reliable source of information. However, physicians did not always proactively discuss HZ vaccination due to time constraints and a perceived need to prioritize other vaccinations including influenza and pneumococcal vaccines. Initiatives are needed to improve public awareness of HZ and its complications, in terms of overall impact on individuals and society, and highlight the important role of physicians in recommending vaccination.

Factors influencing adverse events following COVID-19 vaccination

Various novel platform technologies have been used for the development of COVID-19 vaccines. In this nested cohort study among healthcare workers in Australia and Brazil who received three different COVID-19-specific vaccines, we (a) evaluated the incidence of adverse events following immunization (AEFI); (b) compared AEFI by vaccine type, dose and country; (c) identified factors influencing the incidence of AEFI; and (d) assessed the association between reactogenicity and vaccine anti-spike IgG antibody responses. Of 1302 participants who received homologous 2-dose regimens of ChAdOx1-S (Oxford-AstraZeneca), BNT162b2 (Pfizer-BioNTech) or CoronaVac (Sinovac), 1219 (94%) completed vaccine reaction questionnaires. Following the first vaccine dose, the incidence of any systemic reaction was higher in ChAdOx1-S recipients (374/806, 46%) compared with BNT162b2 (55/151, 36%; p = 0.02) or CoronaVac (26/262, 10%; p < 0.001) recipients. After the second vaccine dose, the incidence of any systemic reaction was higher in BNT162b2 recipients (66/151, 44%) compared with ChAdOx1-S (164/806, 20%; p < 0.001) or CoronaVac (23/262, 9%; p < 0.001) recipients. AEFI risk was higher in younger participants, females, participants in Australia, and varied by vaccine type and dose. Prior COVID-19 did not impact the risk of AEFI. Participants in Australia compared with Brazil reported a higher incidence of any local reaction (170/231, 74% vs 222/726, 31%, p < 0.001) and any systemic reaction (171/231, 74% vs 328/726, 45%, p < 0.001), regardless of vaccine type. Following a primary course of ChAdOx1-S or CoronaVac vaccination, participants who did not report AEFI seroconverted at a similar rate to those who reported local or systemic reactions. In conclusion, we found that the incidence of AEFI was influenced by participant age and COVID-19 vaccine type, and differed between participants in Australia and Brazil.

Factors Influencing COVID-19 Vaccine Hesitancy in Pregnant and Breastfeeding/Puerperium Women: A Cross-Sectional Study

Vaccination among pregnant and breastfeeding women is critical for protecting this vulnerable population and their children. COVID-19 vaccination is recommended both during pregnancy and breastfeeding; however, we still do not fully understand the determinants that influence hesitancy towards COVID-19 vaccination. This study aimed to identify the determinants of vaccine hesitancy in pregnant and breastfeeding, puerperium women. A multicenter, cross-sectional study, involving 435 pregnant and breastfeeding women, was conducted. Vaccination hesitancy was evaluated by administering the Vaccination Attitudes (VAX) Scale and the Zung Anxiety Self-Assessment Scale (SAS) was adopted to measure anxiety levels. Overall, 14% of the participants reported that they did not receive the COVID-19 vaccine, and 78.3% received their first dose during pregnancy or while breastfeeding. The descriptive statistics for the VAX scale showed a total mean score of 3.35 (±1.6), and 75% of participants reported an anxiety index equal to or lower than the threshold. Vaccine hesitancy increased as "adverse events after vaccination" increased (p < 0.01), while SAS levels positively correlated with the participants' mean age (p < 0.05). Investigating the factors influencing vaccine hesitancy enables the development of targeted health policies and SARS-CoV-2 vaccination programs.

Preferences regarding COVID-19 vaccination among 12,000 adults in China: A cross-sectional discrete choice experiment

Understanding public preferences concerning vaccination is critical to inform pandemic response strategies. To investigate Chinese adults' preferences regarding COVID-19 vaccine attributes, we conducted a cross-sectional online survey in 12,000 Chinese adults in June-July, 2021. Participants were requested to answer a series of discrete choice questions related to hypothetical COVID-19 vaccines. Using mixed logit models, our analysis revealed that participants had a higher preference for COVID-19 vaccines with longer duration of protection (coefficient: 1.272, 95% confidence interval [1.016 to 1.529]) and higher efficacy (coefficient: 1.063, [0.840, 1.287]). Conversely, participants demonstrated a lower preference associated with higher risk of rare but serious side-effects (coefficient: -1.158, [-1.359, -0.958]), oral administration (coefficient: -0.211, [-0.377, -0.046]), more doses (coefficient: -0.148, [-0.296, 0.000]) and imported origin (coefficient: -0.653, [-0.864, -0.443]). Moreover, preferences were heterogeneous by individual factors: highly educated participants were more sensitive to the negative vaccine attributes including price (coefficient -0.312, [-0.370, -0.253]) and imported vaccine (coefficient -0.941, [-1.186, -0.697]); there was also substantial heterogeneity in vaccine preferences with respect to age group, marital status, work status, income, chronic diagnosis history, COVID-19 vaccination history and geographic regions. As the first study of examining the public preferences for COVID-19 vaccine in China with a large nationwide sample of 12,000 adults, our results indicate that future vaccine should pose lower risk, possess longer protection period, have higher efficacy, be domestically produced, and have lower costs to increase the COVID-19 vaccination coverage. Our current study findings from this study provide insights and recommendations for not only COVID-19 vaccine design but also vaccine attribute preferences to increase vaccine uptake in potential future pandemics.

Revaccination outcomes among adolescents and adults with suspected hypersensitivity reactions following COVID-19 vaccination: A Canadian immunization research network study

BACKGROUND

COVID-19 vaccination has been associated with anaphylaxis and hypersensitivity reactions. Infectious disease physicians and allergists in the Canadian Special Immunization Clinic (SIC) Network developed guidance for evaluating patients with adverse events following immunization (AEFI) including suspected hypersensitivity. This study evaluated management and adverse event recurrence following subsequent COVID-19 vaccinations.

METHODS

Individuals aged 12 years and older enrolled at participating SICs before February 28, 2023 who were referred for suspected or diagnosed hypersensitivity reaction following COVID-19 vaccination, or for prevaccination assessment of suspected allergy to a COVID-19 vaccine component were included. De-identified clinical assessments and revaccination data, captured in a centralized database, were analyzed. The Brighton Collaboration case definition (BCCD) for anaphylaxis (2023 version) was applied.

RESULTS

The analysis included 206 participants from 13 sites: 26 participants referred for pre-vaccination assessment and 180 participants referred for adverse events following COVID-19 vaccination (15/180 [8.3%] with BCCD confirmed anaphylaxis, 84 [46.7%] with immediate hypersensitivity symptoms not meeting BCCD, 33 [18.3%] with other diagnosed hypersensitivity reactions, and 48 [26.7%] participants with a final diagnosis of non-hypersensitivity AEFI). Among participants referred for AEFIs following COVID-19 vaccination, 166/180 (92.2%) were recommended for COVID-19 revaccination after risk assessment, of whom 158/166 (95.2%) were revaccinated (all with a COVID-19 mRNA vaccine). After revaccination, 1/15 (6.7%) participants with prior anaphylaxis, 1/77 (1.3%) with immediate hypersensitivity not meeting criteria for anaphylaxis and 1/24 (4.2%) with other physician diagnosed hypersensitivity developed recurrent AEFI symptoms that met the BCCD for anaphylaxis. All 26 participants referred pre-vaccination, including 9 (34.6%) with history of polyethylene glycol-asparaginase reactions, were vaccinated without occurrence of immediate hypersensitivity symptoms.

CONCLUSIONS

Most individuals in this national cohort who experienced a hypersensitivity event following COVID-19 vaccination and were referred for specialist review were revaccinated without AEFI recurrence, suggesting that specialist evaluation can facilitate safe revaccination.

Sex and gender differences in adverse events following influenza and COVID-19 vaccination

INTRODUCTION

Active and passive surveillance studies have found that a greater proportion of females report adverse events (AE) following receipt of either the COVID-19 or seasonal influenza vaccine compared to males. In a predominately young adult female population of healthcare workers, we sought to determine the intersection of biological sex and sociocultural gender differences in prospective active reporting of vaccine outcomes, which remains poorly characterized.

METHODS

This cohort study enrolled Johns Hopkins Health System healthcare workers (HCWs) who were recruited from the mandatory annual fall 2019-2022 influenza vaccine and the fall 2022 COVID-19 bivalent vaccine campaigns. Vaccine recipients were enrolled the day of vaccination and AE surveys were administered two days post-vaccination for bivalent COVID-19 and influenza vaccine recipients. Data were collected regarding the presence of a series of solicited local and systemic AEs. Open-ended answers about participants' experiences with AEs also were collected for the COVID-19 vaccine recipients.

RESULTS

Females were more likely to report local AEs after either influenza (OR = 2.28, p = 0.001) or COVID-19 (OR = 2.57, p = 0.008) vaccination compared to males, regardless of age or race. Males and females had comparable probabilities of reporting systemic AEs after either influenza (OR = 1.18, p = 0.552) or COVID-19 (OR = 0.96, p = 0.907) vaccination. Hormonal birth control use did not impact the rates of reported AEs following influenza vaccination among reproductive-aged female HCWs. Women reported more interruptions in their daily routine following COVID-19 vaccination than men and were more likely to seek out self-treatment. More women than men scheduled their COVID-19 vaccination before their days off in anticipation of AEs.

CONCLUSIONS

Our findings highlight the need for sex- and gender-inclusive policies to inform more effective mandatory occupational health vaccination strategies. Further research is needed to evaluate the potential disruption of AEs on occupational responsibilities following mandated vaccination for healthcare workers, a predominately female population, and to more fully characterize the post-vaccination behavioral differences between men and women.

Estimating COVID-19 vaccine acceptance in pregnant and lactating women: a cross-sectional study in Lebanon

BACKGROUND

The COVID-19 pandemic highlights vaccination's critical role in reducing morbidity and mortality, depending on public attitude. This study aims to identify the estimates of COVID-19 vaccine acceptance in pregnant and lactating women, as well as associated potential factors.

METHODS

A cross-sectional study was conducted between August and September 2021, through an online survey and with a paper survey distributed in gynecology and pediatric clinics. Pregnant and breastfeeding women aged 18 years and above were recruited. The attitude scale was created specifically for evaluating attitudes towards the COVID-19 vaccine.

RESULTS

In total, 207 women participated, with 132 breastfeeding, 74 pregnant and 1 experiencing both conditions. Of these, one hundred and twenty women (58%) considered themselves at risk for COVID-19 infection. In addition, 51.7% (n = 107) of women expressed the intent to receive the vaccine once available. A multivariable linear regression was conducted taking the COVID-19 vaccination attitude scale as a dependent variable. The results revealed an R-squared value of 0.558, indicating that approximately 55.8% of the variance in the attitude scale was accounted for by the included predictors. The results showed that preventive measures (ß=2.25, 95% Confidence Interval (CI) [1.02; 3.48], p < 0.001), preference for vaccines made in Europe and America (ß=1.23; 95% CI [0.69-1.77], p < 0.001), protect yourself for getting sick (ß=4.22, 95% Confidence Interval (CI) [2.83; 5.61], p < 0.001) and belief in the importance of vaccination for themselves and their baby (ß=3.49; 95% CI [2.01; 4.98], p < 0.001) were associated with a positive attitude towards vaccination. Conversely, experiencing a previous bad reaction to a vaccine (ß= -1.35; 95% CI [0.85-1.85], p < 0.001) and concerns regarding COVID-19 vaccine safety (ß= -4.09; 95% CI [-5.98; -2.21], p < 0.001) were associated with a negative attitude towards vaccination.

CONCLUSION

Our findings reveal that COVID-19 vaccine acceptability among pregnant and breastfeeding women, amidst the pandemic was insufficient to meet community immunity. The identified reasons for vaccine reluctance, notably concerns about safety for both personal health and the health of their pregnancy or newborns, along with insufficient information about the vaccine, underscore the pressing need to address these factors to improve immunization rates.

Prediction and detection of side effects severity following COVID-19 and influenza vaccinations: utilizing smartwatches and smartphones

Vaccines stand out as one of the most effective tools in our arsenal for reducing morbidity and mortality. Nonetheless, public hesitancy towards vaccination often stems from concerns about potential side effects, which can vary from person to person. As of now, there are no automated systems available to proactively warn against potential side effects or gauge their severity following vaccination. We have developed machine learning (ML) models designed to predict and detect the severity of post-vaccination side effects. Our study involved 2111 participants who had received at least one dose of either a COVID-19 or influenza vaccine. Each participant was equipped with a Garmin Vivosmart 4 smartwatch and was required to complete a daily self-reported questionnaire regarding local and systemic reactions through a dedicated mobile application. Our XGBoost models yielded an area under the receiver operating characteristic curve (AUROC) of 0.69 and 0.74 in predicting and detecting moderate to severe side effects, respectively. These predictions were primarily based on variables such as vaccine type (influenza vs. COVID-19), the individual's history of side effects from previous vaccines, and specific data collected from the smartwatches prior to vaccine administration, including resting heart rate, heart rate, and heart rate variability. In conclusion, our findings suggest that wearable devices can provide an objective and continuous method for predicting and monitoring moderate to severe vaccine side effects. This technology has the potential to improve clinical trials by automating the classification of vaccine severity.

Acute Pancreatitis Induced by COVID-19 Vaccine: A Systematic Review

Acute pancreatitis, marked by sudden inflammation of the pancreas, presents a complex spectrum of causative factors including gallstone obstruction, alcohol abuse, and viral infections. Recent studies have illuminated the emergence of vaccine-induced acute pancreatitis, notably associated with COVID-19 vaccinations, presenting diverse mechanisms ranging from direct viral-mediated injury to autoimmune reactions. Understanding this link is pivotal for public health, yet challenges persist in identifying and managing cases post-vaccination. Comprehensive literature reviews employing the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement outline the potential pathways and mechanisms leading to vaccine-induced pancreatitis, emphasizing the need for deeper investigations into underlying health conditions and modifications to vaccine components. Notably, the rare occurrences of vaccine-induced pancreatitis extend beyond COVID-19 vaccines, with reports also documenting associations with measles, mumps, and rubella (MMR), human papillomavirus (HPV), and other viral vaccinations. Mechanistically, hypotheses such as molecular mimicry and immunologic injury have been proposed, necessitating ongoing vigilance and exploration. Regulatory agencies play a crucial role in monitoring and communicating vaccine safety concerns, emphasizing transparency to address potential risks and maintain public trust. Understanding and communicating these rare adverse events with transparency remain integral for informed vaccination policies and to allay concerns surrounding vaccine safety.

Sex and gender differences in adverse events following receipt of influenza and COVID-19 vaccination among healthcare workers

Introduction

Active and passive surveillance studies have found that a greater proportion of females report adverse events (AE) following receipt of either the COVID-19 or seasonal influenza vaccine compared to males. We sought to determine the intersection of biological sex and sociocultural gender differences in prospective active reporting of vaccine outcomes, which remains poorly characterized.

Methods

This cohort study enrolled Johns Hopkins Health System healthcare workers (HCWs) who were recruited from the annual fall 2019-2022 influenza vaccine and the fall 2022 COVID-19 bivalent vaccine campaigns. Vaccine recipients were enrolled the day of vaccination and AE surveys were administered two days post-vaccination (DPV) for bivalent COVID-19 and Influenza vaccine recipients. Data were collected regarding the presence of a series of solicited local and systemic AEs. Open-ended answers about participants' experiences with AEs also were collected for the COVID-19 vaccine recipients.

Results

Females were more likely to report local AEs after influenza (OR=2.28, p=0.001) or COVID-19 (OR=2.57, p=0.008) vaccination compared to males, regardless of age or race. Males and females had comparable probabilities of reporting systemic AEs after influenza (OR=1.18, p=0.552) or COVID-19 (OR=0.96, p=0.907) vaccination. Exogenous hormones from birth control use did not impact the rates of reported AEs following COVID-19 vaccination among reproductive-aged female HCWs. Women reported more interruptions in their daily routine following COVID-19 vaccination than men and were more likely to seek out self-treatment. More women than men scheduled their COVID-19 vaccination before their days off in anticipation of AEs.

Conclusions

Our findings highlight the need for sex- and gender-inclusive policies to inform more effective occupational health vaccination strategies. Further research is needed to evaluate the potential disruption of AEs on occupational responsibilities following mandated vaccination for healthcare workers and to more fully characterize the post-vaccination behavioral differences between men and women.

KEY MESSAGE

What is already known on this topic: ⇒ Among diversely aged adults 18-64 years, females report more AEs to vaccines, including the influenza and COVID-19 vaccines, than males.⇒ Vaccine AEs play a role in shaping vaccine hesitancy and uptake.⇒ Vaccine uptake related to influenza and COVID-19 are higher among men than women.⇒ Research that addresses both the sex and gender disparities of vaccine outcomes and behaviors is lacking.What this study adds: ⇒ This prospective active reporting study uses both quantitative and qualitative survey data to examine sex and gender differences in AEs following influenza or COVID-19 vaccination among a cohort of reproductive-aged healthcare workers.How this study might affect research, practice, or policy: ⇒ Sex and gender differences in AEs and perceptions relating to vaccination should drive the development of more equitable and effective vaccine strategies and policies in occupational health settings.

Assessing vaccine hesitancy and health literacy using a new Italian vaccine confidence index and a modified Italian medical term recognition test: A cross-sectional survey on Italian parents

The decline in children's vaccination coverage and the resurgence of preventable infectious diseases draw attention to parents' vaccine hesitancy. Our study introduces two validated tools to independently assess vaccine hesitancy and health literacy among parents with school-age children. We developed a Vaccine Confidence Index (VCI) from 10 Likert items, exploring their relationships through exploratory and confirmatory factor analyses. We modified the IMETER (Italian medical term recognition test) to measure health literacy. We assessed the internal consistency of the modified IMETER and the 10 Likert items using Cronbach's alpha test (α) and McDonald's omega total coefficient (ω) with good results (ω = 0.92, α = 0.90; ω = 0.87, α = 0.82 respectively). We used these tools within a questionnaire conducted on 743 parents recruited from pediatric clinic waiting rooms in Italy, collecting demographic data, information sources on vaccines and vaccine-preventable diseases knowledge. The VCI resulting from factor analyses consisted of six items on a ten-point Likert scale, reflecting the ratio of positive to negative items. The survey revealed significant variations in the VCI according to individual features such as education, use of social networks, or Health institutions as sources of information. Multivariate logistic regression identified an association between vaccine intention and the VCI. Health literacy was functional for 91.2% of participants, but knowledge about vaccine-preventable diseases was generally low. The VCI showed no significant association with health literacy and vaccine-preventable diseases knowledge. The VCI and the modified IMETER effectively assess vaccination attitude and health literacy, offering valuable public health tools for tailoring vaccination campaigns to hesitant population subgroups.

Mapping the Cognitive Biases Related to Vaccination: A Scoping Review of the Literature

INTRODUCTION

Human behavior and understanding of the vaccine ecosystem play a critical role in the vaccination decision-making process. The objective of this study was to understand different cognitive biases that may lead to vaccine acceptance or hesitancy.

METHODS

The eligibility criteria for this scoping review was vaccination-related cognitive bias studies published in the English language from inception to April 2022 and available on PubMed, Embase, and Google Scholar. It included all geographical locations and individuals of all age groups and excluded studies focusing on (i) clinical trials of vaccines, (ii) vaccine research conduct bias, (iii) cognitive delay, or (iv) statistical biases. The search method also included reviewing references in the retrieved articles.

RESULTS

Overall, 58 articles were identified, and after screening, 19 were included in this study. Twenty-one cognitive biases with the potential to affect vaccination decision-making were observed. These biases were further grouped into three broad categories: cognitive biases seen while processing vaccine-related information, during vaccination-related decision-making, and due to prior beliefs regarding vaccination.

CONCLUSIONS

This review identified critical cognitive biases affecting the entire process of vaccination that can influence research and public health efforts both positively and negatively. Recognizing and mitigating these cognitive biases is crucial for maintaining the population's level of trust in vaccination programs around the world.

Unraveling the association between vaccine attitude, vaccine conspiracies and self-reported side effects following COVID-19 vaccination among nurses and physicians in Jordan

Background

The negative impact of vaccine conspiracies is linked with negative health behavior. The aim of the current study was to examine the association between attitudes toward booster COVID-19, influenza, and monkeypox (mpox) vaccinations with post-COVID-19 vaccine side effects, vaccine conspiracies, and attitude towards mandatory vaccination among nurses and physicians in Jordan.

Methods

A structured closed-ended questionnaire was used to collect data on demographics, COVID-19 history, COVID-19 vaccine type and doses received, self-reported side effects post-COVID-19 vaccination, acceptance of booster COVID-19, seasonal influenza, and mpox vaccinations, attitudes towards mandatory vaccination, and beliefs in vaccine conspiracies.

Results

The study sample comprised a total of 341 participants. Acceptance of yearly booster COVID-19 vaccination was expressed by 46.6% of the sample, while 73.3% accepted seasonal influenza vaccination, and only 37.0% accepted mpox vaccination. A higher frequency of self-reported side effects following the first COVID-19 vaccine dose was associated with embrace of vaccine conspiracies and vaccine type. For the second vaccine dose, a higher frequency of self-reported side effects was associated with the embrace of vaccine conspiracies, older age, and affiliation to private sector. In multinomial logistic regression analyses, the lower embrace of vaccine conspiracies was associated with lower odds of reporting side effects post-COVID-19 vaccination. The lower embrace of vaccine conspiracies and favorable attitude towards mandatory vaccination were associated with the willingness to get COVID-19, influenza, and mpox vaccinations.

Conclusion

The study findings highlighted the negative impact of embracing vaccine conspiracies on health-seeking behavior among nurses and physicians. The findings indicated that the willingness to get vaccinated was associated with lower endorsement of vaccine conspiracies. Additionally, the lower embrace of vaccine conspiracies was associated with a lower frequency of self-reported side effects following COVID-19 vaccination. These results emphasize the importance of addressing vaccine misinformation and promoting accurate information to ensure optimal vaccine uptake and public health outcomes.

Impact of Actor's Initial State of Engagement in a Course of Action on Judgements of Post-decisional Regret and Joy: Revisiting Kahneman and Tversky (1982)

According to the phenomenon commonly known as action effect and vastly replicated across the judgment and decision-making literature, more regret is associated with decisions resulting from action than inaction. Action vs. inaction, however, might either refer to change vs. no change or doing something vs. not doing something. The purpose of this study was to examine the effect of this variation in operationalization of action-inaction on the strength of action effect, for both positive and negative outcomes, across four different domains of employment, finance, education, and health. This was an experimental scenario-based study (N = 215) with four between-subjects conditions varying in outcome valence and the actor's initial state as either engaged or non-engaged in a particular course of action. Action effect was found to be stronger with respect to the initially engaged than the initially non-engaged decision-maker (ηp2 = .04), indicating that action as change results in a stronger action effect than action as doing something. The effect of the initial state was also moderated by domain. In addition, we both replicated and went beyond prior empirical literature regarding the effect of outcome valence and domain on action effect, with our findings being mostly consistent across joy and regret. Findings are discussed in light of the norm theory and its key concept of normality and contribute to the literature on moderators of action effect.

Barriers to optimal AEFI surveillance and documentation in Nigeria: Findings from a qualitative survey

Effective spontaneous AEFI reporting is the first step to ensuring vaccine safety. Half of the global population lives in countries with weak vaccine safety monitoring systems, especially in the African, Eastern Mediterranean, and Western Pacific regions. Further, Immunisation services have been upscaled without commensurate effective AEFI surveillance systems. Hence, this study aims to comprehensively investigate the impediments to an effective AEFI surveillance system. Given the programmatic and regulatory implications, understanding these impediments would facilitate the development and implementation of policies and strategies to strengthen the AEFI surveillance system in Nigeria. A qualitative research design (using a grounded theory approach) was employed by conducting ten key informant interviews and two Focus Group Discussion sessions among the study population to identify the barriers impeding optimal AEFI surveillance and documentation in Nigeria. This study found that the AEFI surveillance system is in place in Nigeria. However, its functionality is sub-optimal, and the potential capacity is yet to be fully harnessed due to health systems and socio-ecological impediments. The identified impediments are human-resource-related issues- knowledge gaps; limited training; lack of designated officers for AEFI; excessive workload; poor supportive supervision and attitudinal issues; caregiver's factor; governance and leadership- moribund AEFI committee; lack of quality supervisory visit and oversight and weak implementation of AEFI policy guidance. Others include funding and logistics issues- no dedicated budget provision and weak referral mechanism; insecurity; socio-economic and infrastructural deficits- poverty, geographical barriers, limited ICT skills, and infrastructure; and poor feedback and weak community engagement by the health workers. Findings from this study provide empirical evidence and serve as an advocacy tool for vaccine pharmacovigilance strengthening in Nigeria. Addressing the impediments requires health system strengthening and a whole-of-the-society approach to improve vaccine safety surveillance, restore public confidence and promote vaccine demand, strengthen PHC services, and contribute to attaining UHC and SDGs.

Failure to Complete Multidose Vaccine Series in Early Childhood

BACKGROUND

Most early childhood immunizations require 3 to 4 doses to achieve optimal protection. Our objective was to identify factors associated with starting but not completing multidose vaccine series.

METHODS

Using 2019 National Immunization Survey-Child data, US children ages 19 to 35 months were classified in 1 of 3 vaccination patterns: (1) completed the combined 7-vaccine series, (2) did not initiate ≥1 of the 7 vaccine series, or (3) initiated all series, but did not complete ≥1 multidose series. Associations between sociodemographic factors and vaccination pattern were evaluated using multivariable log-linked binomial regression. Analyses accounted for the survey's stratified design and complex weighting.

RESULTS

Among 16 365 children, 72.9% completed the combined 7-vaccine series, 9.9% did not initiate ≥1 series, and 17.2% initiated, but did not complete ≥1 multidose series. Approximately 8.4% of children needed only 1 additional vaccine dose from 1 of the 5 multidose series to complete the combined 7-vaccine series. The strongest associations with starting but not completing multidose vaccine series were moving across state lines (adjusted prevalence ratio [aPR] = 1.45, 95% confidence interval [CI]: 1.18-1.79), number of children in the household (2 to 3: aPR = 1.29, 95% CI: 1.05-1.58; 4 or more: aPR = 1.68, 95% CI: 1.30-2.18), and lack of insurance coverage (aPR = 2.03, 95% CI: 1.42-2.91).

CONCLUSIONS

More than 1 in 6 US children initiated but did not complete all doses in multidose vaccine series, suggesting children experienced structural barriers to vaccination. Increased focus on strategies to encourage multidose series completion is needed to optimize protection from preventable diseases and achieve vaccination coverage goals.

"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.

The Effects of Non-Pharmaceutical Interventions on COVID-19 Cases, Hospitalizations, and Mortality: A Systematic Literature Review and Meta-Analysis

Introduction

To assess the effects of various non-pharmaceutical interventions (NPI) on cases, hospitalizations, and mortality during the first wave of the COVID-19 pandemic.

Methods

To empirically investigate the impacts of different NPIs on COVID-19-related health outcomes, a systematic literature review was conducted. We studied the effects of 10 NPIs on cases, hospitalizations, and mortality across three periodic lags (2, 3, and 4 weeks-or-more following implementation). Articles measuring the impact of NPIs were sourced from three databases by May 10, 2022, and risk of bias was assessed using the Newcastle-Ottawa scale.

Results

Across the 44 papers, we found that mask wearing corresponded to decreased per capita cases across all lags (up to -2.71 per 100,000). All NPIs studied except business and bar/restaurant closures corresponded to reduced case growth rates in the two weeks following implementation, while policy stringency and travelling restrictions were most effective after four. While we did not find evidence of reduced deaths in our per capita estimates, policy stringency, masks, SIPOs, limited gatherings, school and business closures were associated with decreased mortality growth rates. Moreover, the two NPIs studied in hospitalizations (SIPOs and mask wearing) showed negative estimates.

Conclusions

When assessing the impact of NPIs, considering the duration of effectiveness following implementation has paramount significance. While some NPIs may reduce the COVID-19 impact, others can disrupt the mitigative progression of containing the virus. Policymakers should be aware of both the scale of their effectiveness and duration of impact when adopting these measures for future COVID-19 waves.

The readiness of the spontaneous reporting system for COVID-19 vaccines safety monitoring in Croatia

We aimed to identify whether a spontaneous reporting system (SRS) in Croatia could timely identify and confirm signals for COVID-19 vaccines. Post-marketing spontaneous reports of adverse drug reactions (ADRs) following COVID-19 immunisation reported to the Agency for Medicinal Products and Medical Devices of Croatia (HALMED) were extracted and analysed. 6624 cases reporting 30 655 ADRs following COVID-19 immunisation were received from 27^th December 2020 to 31st December 2021. Available data in those cases were compared with data available to the EU network at the time when signals were confirmed and minimisation measures were implemented. 5032 cases, reporting 22 524 ADRs, were assessed as non-serious, and 1,592 cases, reporting 8,131 ADRs as serious. The most reported serious ADRs, which were listed in the MedDRA Important medical events terms list, were syncope (n = 58), arrhythmia (n = 48), pulmonary embolism (n = 45), loss of consciousness (n = 43), and deep vein thrombosis (n = 36). The highest reporting rate had Vaxzevria (0.003), followed by Spikevax and Jcovden (0.002), and Comirnaty (0.001). Potential signals were identified, however, they couldn't be timely confirmed solely on cases retrieved by SRS. In order to overcome the limitations of SRS, active surveillance and post-authorisation safety studies of vaccines should be implemented in Croatia.

COVID-19 anti-vaccine attitude and hesitancy

High vaccination rates are required around the world to create herd immunity and terminate the current COVID-19 pandemic growth. With the steady rise in COVID-19 vaccine supplies, hesitancy and rejection to be vaccinated has become a problem worldwide for large vaccine coverage. Understanding the causes of vaccine avoidance or hesitancy can help to increase vaccination intentions in the general population. A number of factors contributed to increasing hesitancy. Some causes of COVID-19 vaccine hesitancy include anti-vaccine myths and confusing messages about some severe side effects of few vaccines, confusion over protection levels, poor health literacy (lack of accurate knowledge about vaccines and virus), deficient legal liability from the vaccine manufacturers, political and economic intentions, mistrust and suspicion of medical companies, concern of efficacy against to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants, safety concerns (elderly, people with preexisting comorbidities) and some socio-demographic factors. Urgent interventions and policies targeting the corresponding factors are needed. Recognizing obstacles to vaccine uptake helps in the development of effective solutions to solve them. Evidence-based and behaviorally guided approaches should be used to achieve high acceptance and uptake.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-022-01018-y.

The Prevalence of COVID-19 Vaccine Hesitancy Among the Black Asian Ethnic Minority in New South Wales, Australia

INTRODUCTION

Vaccination provides a cost-effective approach to controlling the COVID-19 pandemic. The success of vaccination depends on global preparedness and acceptance of the new vaccines, and this is threatened by vaccine hesitancy worldwide. This study aimed to measure the prevalence of COVID-19 vaccine hesitancy, attitudes, and contributing factors in the Black Asian Ethnic Minority (BAME) of New South Wales (NSW), Australia.  Aim: This study aimed to measure the prevalence of COVID-19 vaccine hesitancy and identify contributing factors leading to vaccine hesitancy in the Black Asian and Ethnic Minority (BAME) in NSW.

METHOD

A cross-sectional study was conducted among the BAME community in NSW; over 12 weeks, from January 3^rd, 2022, to March 28^th, 2022. The study used the pre-existing previously known 5Cs model (confidence, constraints, complacency, calculation, and collective responsibility) to assess reasons for hesitancy. The questionnaire was distributed in English using social media platforms: Facebook and WhatsApp.

RESULTS

The study received 101 respondents over 18 years from all states in Australia from BAME communities, males and females, with different educational levels, employment sectors, marital statuses, co-existing chronic medical conditions, previous COVID-19 infection status, and COVID-19 vaccine received. Of these, 56 respondents were from NSW. Our findings revealed a high prevalence of COVID-19 vaccine hesitancy among the BAME community in NSW, with 72.8% of respondents demonstrating hesitancy/reluctance due to various attitudes identified by the 5Cs model. Despite this high hesitancy, 98.2% of the participants had received at least one to three vaccine doses.

CONCLUSION

 Even in populations with high vaccine uptake, it is still essential to address vaccine hesitancy and provide ongoing education about the importance of vaccination, particularly as new variants of COVID-19 continue to emerge and the need for booster shots may arise. This can help ensure continued protection against the virus and prevent future outbreaks.

Medical and public health professionals' perceived facilitators and barriers of human papillomavirus (HPV) vaccination among African American adolescents in Shelby County, Tennessee

Human papillomavirus (HPV) infects nearly 85% of sexually active Americans during their lifetime, causing most cervical and five other cancers. Routine HPV vaccination is recommended for adolescents to prevent HPV-attributable cancers, but HPV vaccination coverage remains low, especially in Tennessee. In 2021, 54.6% of the population in Shelby County, Tennessee was Black or African American, reporting higher rates of new cervical cancer cases than other counties in Tennessee. While medical and public health professionals (HPs) play a critical role in promoting vaccination coverage, little is known about the factors HPs perceive to influence HPV vaccination for this population. This study sought to explore HPs' perceived facilitators and barriers of HPV vaccination among African American adolescents. Qualitative individual interviews with 26 HPs in Shelby County were conducted between October 2019 and February 2020. Interpretive content analysis of the interview data guided by the socio-ecological model revealed several important themes regarding the facilitators and barriers across the individual, interpersonal, and community levels. At the individual level, parental vaccine hesitancy emerged as a leading barrier to HPV vaccination, while appropriate education facilitated the vaccination. At the interpersonal level, a lack of strong provider recommendations impeded HPV vaccination, whereas improved communication skills with patients facilitated the vaccination. Finally, the community-level barriers included a lack of education and social/religious norms; the community-level facilitators included community outreach efforts. HPs should consider development of comprehensive community-based approaches that leverage the facilitators and barriers at multiple levels to increase HPV vaccination among African American adolescents in this region.

Oral side effects of COVID-19 vaccines in 32 European countries: Analysis of EudraVigilance reports

The recent reports of oral side effects (SEs) following COVID-19 vaccination warrant further investigation into their prevalence, severity, and aetiology. This study was conducted to synthesize the first-ever population-level evidence about oral SEs of COVID-19 vaccines in Europe. The European Union Drug Regulating Authorities Pharmacovigilance (EudraVigilance) database was accessed in August 2022 to extract summary data of all potential oral SEs reported after COVID-19 vaccination. The data were reported descriptively and cross-tabulated to facilitate sub-group analysis per vaccine type, sex, and age group. Dysgeusia was the most commonly reported oral SE (0.381 case per each 100 received reports), followed by oral paraesthesia (0.315%), ageusia (0.296%), lip swelling (0.243%), dry mouth (0.215%), oral hypoaesthesia (0.210%), swollen tongue (0.207%), and taste disorder (0.173%). Females had significantly (Sig. < 0.001) a higher prevalence of all most common (top 20) oral SEs, except for salivary hypersecretion, which was equally prevalent among females and males. The present study revealed a low prevalence of oral SEs, with taste-related, other sensory and anaphylactic SEs being the most common SEs in Europe, similar to what was found earlier among the US population. Future studies should explore the potential risk factors of oral sensory and anaphylactic SEs to verify whether they are causally linked to COVID-19 vaccines.

From COVID-19 vaccine candidates to compulsory vaccination: The attitudes of Italian citizens in the key 7-month of vaccination campaign

INTRODUCTION

The aim of the study is to understand the evolution of COVID-19 vaccine acceptance over the key 7-month vaccine campaign in Italy, a period in which the country moved from candidate vaccines to products administered to the public. The research focus points to evaluate COVID-19 vaccine attitudes in adults and their children, propension towards compulsory vaccination, past and present adherence to anti-flu and anti-pneumococcal vaccines, and the reasons for trust/mistrust of vaccines.

METHODS

Italian residents aged 16->65 years were invited to complete an online survey from September 2020 to April 2021. The survey contained 13 questions: 3 on demographic data; 8 on vaccine attitudes; and 2 open-ended questions about the reasons of vaccine confidence/refusal. A preliminary word frequency analysis has been conducted, as well as a statistical bivariate analysis.

RESULTS

Of 21.537 participants, the confidence of those in favor of the COVID-19 vaccine increases of 50 % and the number of people who wanted more information decreases by two-third. Willingness to vaccinate their children against COVID-19 also increased from 51 % to 66.5 %. Only one-third of the strong vaccine-hesitant participants, i.e. 10 %, remained hostile. Compulsory vaccination showed a large and increasing favor by participants up to 78 %, in a way similar to their propensity for children's mandatory vaccination (70.6 %). Respondents' past and present adherence to anti-flu and anti-pneumococcal vaccines does not predict their intentions to vaccinate against COVID-19. Finally, a semantic analysis of the reasons of acceptance/refusal of COVID-19 vaccination suggests a complex decision-making process revealed by the participants' use of common words in pro-and-cons arguments.

CONCLUSION

The heterogeneity in the COVID-19 vaccine hesitancy, determinants and opinions detected at different ages, genders and pandemic phases suggests that health authorities should avoid one-size-fits-all vaccination campaigns. The results emphasize the long-term importance of reinforcing vaccine information, communication and education needs.

Using Behavioural Science to Help Understand Vaccine Hesitancy

This article is based on a Learning Lounge educational session that took place on 22nd October 2022, as part of Infectious Diseases Society of America (IDSA) IDWeek™ 2022 held in Washington, D.C., USA. The objectives of the Learning Lounge were to enhance understanding of the principal reasons for patients’ vaccine hesitancy based on key sociocultural, behavioural, and psychological factors; identify the general communication ‘cues’ and specific psychosocial objections that signal a patient’s inclination to vaccine bias; and help healthcare professionals (HCP) learn how to address vaccine hesitancy based on patients’ cognitive and behavioural biases. The knowledge shared in this Learning Lounge can help guide and assist HCPs in recognising and addressing vaccine hesitancy, thereby supporting effective conversations with patients and/or their caregivers, and drive more personalised solutions to improve acceptance of vaccinations. The Learning Lounge was hosted by Christopher Graves, Founder and President of the Ogilvy Centre for Behavioral Science, New York, New York, USA., who is an expert on vaccine hesitancy and guiding HCPs on recognising and addressing this phenomenon. Graves was joined by Wendy Wright, Partners in Healthcare Education, LLC, Bedford, New Hampshire, USA, and Todd Wolynn, Kids Plus Pediatrics, Pittsburgh, Pennsylvania, USA, in a roleplay discussion to highlight cognitive biases that are relevant to vaccine hesitancy, and how these might be addressed in clinical practice.

Intention to Vaccinate against COVID-19 among Young Adults: The Role of Conspiratorial Thinking

The anti-scientific and anti-vaccine movements gained momentum amidst the health and socio-economic crisis brought about by the COVID-19 pandemic. These widespread pseudoscientific beliefs and the endorsement of conspiracy theories likely contributed to the COVID-19 vaccine hesitancy. The aim of this study was to explore which variables best differentiated between groups of vaccinated (n = 289), vaccine-hesitant (n = 106), and vaccine-refusing (n = 146) young adults. The study was conducted online at the beginning of the mass vaccination campaign in Croatia when the vaccine just became available for younger and non-vulnerable members of the general population. The demographic variables, COVID-19 anxiety, and conspiratorial thinking regarding COVID-19 were entered into the discriminant analysis. The function explaining 89.2% of the group differences, mostly between the vaccinated and vaccine-refusing, was largely defined by conspiratorial thinking regarding COVID-19 (0.852), followed by variables with substantially less discriminative power, including COVID-19 anxiety (0.423; lower in the vaccine-refusing group), political orientation (0.486; vaccine-refusing leaning less to the left), financial and educational status (0.435 and 0.304, respectively; both lower in the vaccine-refusing group), and religiosity (0.301; higher in the vaccine-refusing group). These results confirm that among young adults, the decision to vaccinate against COVID-19 might be heavily influenced by one's proclivity to engage in conspiratorial thinking.

Research progress on circular RNA vaccines

Owing to the success of linear mRNA coronavirus disease 2019 (COVID-19) vaccines, biopharmaceutical companies and research teams worldwide have attempted to develop more stable circular RNA (circRNA) vaccines and have achieved some preliminary results. This review aims to summarize key findings and important progress made in circRNA research, the in vivo metabolism and biological functions of circRNAs, and research progress and production process of circRNA vaccines. Further, considerations regarding the quality control of circRNA vaccines are highlighted herein, and the main challenges and problem-solving strategies in circRNA vaccine development and quality control are outlined to provide a reference for circRNA vaccine-related research.

Willingness to receive a vaccine is influenced by adverse events following immunisation experienced by others

An adverse event following immunization (AEFI) can have consequences for an individual's future decision making and may contribute to vaccine hesitancy. AEFIs vary in severity and can be experienced directly (by an individual themselves) or indirectly (through witnessed or recounted events). We sought to measure the prevalence of specific AEFIs and understand which AEFIs have the greatest associations with reduced willingness to receive a vaccine and how injection anxiety may moderate the relationship. We conducted a cross-sectional online survey with both qualitative and quantitative elements in a sample of adults aged 18 years and over in Australia. Nineteen percent of the 1050 respondents reported experiencing an AEFI that they found stressful. Those who experienced an AEFI reported significantly higher levels of injection anxiety than those who did not. Within the group who reported experiencing an AEFI, respondents were significantly less likely to be willing to receive a COVID-19 vaccine if they reported: indirect exposure to an uncommon/rare AEFI compared with other AEFIs (aOR:0.39; 95% CI: 0.18-0.87); indirect exposure to a scientifically unsupported AEFI compared with other AEFIs (aOR:0.18; 95% CI: 0.05-0.57). Direct exposure to an AEFI was not associated with willingness to receive a COVID-19 vaccine. For those who reported experiencing an AEFI, the odds of willingness to receive a COVID-19 vaccine decreased significantly with an increase in injection anxiety (aOR:0.94; 95% CI: 0.9-0.98). Our results suggest that more is needed to mitigate the consequences of AEFIs on vaccine willingness. Empathically acknowledging at a community level, the experience of both real and perceived AEFIs and incorporating accounts of positive vaccination experiences in vaccine hesitancy interventions may be useful.

Zika virus knowledge and vaccine acceptance among undergraduate students in Guayaquil, Ecuador

Purpose

Zika virus (ZIKV) was declared a Public Health Emergency of International Concern (PHEIC) in 2016. Concerns surrounding the effects of ZIKV persist today and several vaccine candidates are currently in various stages of development worldwide. There is limited research on ZIKV vaccine acceptability worldwide, and little research specific to Latin American countries. This research aims to identify the general beliefs and acceptance of a potential ZIKV vaccine in the undergraduate population at Escuela Superior Politécnica del Litoral (ESPOL) in Guayaquil, Ecuador.

Methods

Between January and November 2019, 429 undergraduate students at ESPOL responded anonymously to a ZIKV vaccine survey. Frequencies, percentages, simple correspondence analysis, and bivariate inferential analyses were conducted using Kendall's tau-b test. Tests explored associations between likelihood of receiving a ZIKV vaccine and demographic, ZIKV information seeking, ZIKV psychosocial variables, and ZIKV information source variables.

Results

Among the eligible participants, 241 (56.2%) were willing to receive a ZIKV vaccine if one was made commercially available. Most students were male (61.5%), age 20-25 (63.3%), and of mixed (Mestizo) race (95.3%). Results provided insight into student's knowledge on ZIKV, revealed television as the most common information source, and found most students were willing to receive a ZIKV vaccine were one to become available. Bivariate results revealed most respondents reported feeling neutral or likely to receive a ZIKV vaccine regardless of their agreeability with ZIKV information seeking behavior and psychosocial variables.

Conclusions

This study provides insight into ZIKV knowledge among ESPOL university students and reveals most respondents obtained ZIKV related information from television. The most common reason for not wanting to receive a hypothetical ZIKV vaccine was vaccine hesitancy. Likelihood of receiving a ZIKV vaccine was associated with several information seeking behavior and psychosocial variables. Public health campaigns should focus on comprehensive ZIKV education efforts in this population.

From trial to practice: incidence and severity of COVID-19 vaccine side effects in a medically at-risk and vaccine-hesitant community

Background

The rapid authorization and widespread rollout of COVID-19 vaccines in the United States demonstrated a need for additional data on vaccine side effects, both to provide insight into the range and severity of side effects that might be expected in medically-diverse populations as well as to inform decision-making and combat vaccine hesitancy going forward. Here we report the results of a survey of 4825 individuals from southcentral Kentucky who received two doses of either the Pfizer-BioNTech (BNT162b2) or Moderna (mRNA-1273) vaccine between December 14, 2020 and May 1, 2021. As new versions of the vaccine are rolled-out, local initiatives such as this may offer a means to combat vaccine hesitancy in reference to COVID-19, but are also important as we face new viral threats that will necessitate a rapid vaccine rollout, and to combat a growing public distrust of vaccines in general.

Methods

Individuals that received two doses of either BNT162b2 or mRNA-1273 between December 14, 2020 and May 1, 2021 were sent a survey, created by the research team. Respondents were asked to rate the incidence and severity of 15 potential side effects and two related outcomes following each of their two doses of the vaccine. All statistical analyses were carried out using SYSTAT, version 13. The data were analyzed utilizing a range of statistical tests, including chi-square tests of association, Cohen’s h, Kruskal-Wallis test one-way nonparametric ANOVA, least-squares regression, and Wilcoxon signed-ranks test. Significance was assessed using Bonferroni-adjusted criteria within families of tests.

Results

In general, the pattern and severity in side effects was similar to both clinical trial data as well as other published studies. Responses to the mRNA-1273 vaccine were more severe than to BNT162b2, though all were generally in the mild to moderate category. Individuals who reported having previously tested positive for COVID-19 reported stronger responses following the first dose of either vaccine relative to COVID-naïve individuals. The reported severity to the COVID-19 vaccine was positively correlated with self-reported responses to other vaccines.

Conclusions

Our findings allow broad-scale estimates of the nature and severity of reactions one might expect following vaccination within a clinically-diverse community, and provide a context for addressing vaccine hesitancy in communities such as ours, where locally-generated data and communication may be more influential than national trends and statistics in convincing individuals to become vaccinated. Further, we argue this community-based approach could be important in the future in three key ways: 1) as new boosters and modified vaccines re-volatilize vaccine hesitancy, 2) as new vaccines receive similar testing and rapid authorization, and 3) to combat vaccine hesitancy in other arenas (e.g., annual vaccines, childhood vaccines).

Understanding the Attitudes and Willingness of Adult Chinese Patients with Rheumatic Diseases Towards COVID-19 Vaccination

BACKGROUND

The SARS-CoV-2 pandemic has imposed substantial health and economic burdens on the societies. COVID-19 vaccination is the most effective method of controlling the epidemic. This study assessed the attitude, willingness, and related factors of adult patients with rheumatic diseases (RDs) in China towards COVID-19 vaccination and identified their reasons for being vaccinated.

METHODS

 A cross-sectional survey was administered to patients with rheumatic diseases from July 18 to August 18, 2021, using an online questionnaire. Logistic regression analysis was performed to examine the data.

RESULTS

We analyzed data drawn from 464 participants who provided valid responses. A total of 324 (69.83%) RD patients were not willing to be vaccinated, of which 76.97% believed that COVID-19 vaccination might exacerbate the diseases symptoms. Logistic regression analysis showed that a combination of experiencing systemic damage, being in the acute attack stage of the disease, and fear of the adverse impact of vaccination on rheumatism, etc., were the predominant factors affecting the intentional vaccination rate in adult patients with rheumatic diseases (p < 0.05).

CONCLUSION

The COVID-19 intentional vaccination rate was relatively low in adult Chinese patients with RD. Public health education and the dissemination of government scientific data for patients with RD should be enhanced to increase COVID-19 vaccination rates.

Identifying Modifiable Predictors of COVID-19 Vaccine Side Effects: A Machine Learning Approach

Side effects of COVID-19 or other vaccinations may affect an individual's safety, ability to work or care for self or others, and/or willingness to be vaccinated. Identifying modifiable factors that influence these side effects may increase the number of people vaccinated. In this observational study, data were from individuals who received an mRNA COVID-19 vaccine between December 2020 and April 2021 and responded to at least one post-vaccination symptoms survey that was sent daily for three days after each vaccination. We excluded those with a COVID-19 diagnosis or positive SARS-CoV2 test within one week after their vaccination because of the overlap of symptoms. We used machine learning techniques to analyze the data after the first vaccination. Data from 50,484 individuals (73% female, 18 to 95 years old) were included in the primary analysis. Demographics, history of an epinephrine autoinjector prescription, allergy history category (e.g., food, vaccine, medication, insect sting, seasonal), prior COVID-19 diagnosis or positive test, and vaccine manufacturer were identified as factors associated with allergic and non-allergic side effects; vaccination time 6:00-10:59 was associated with more non-allergic side effects. Randomized controlled trials should be conducted to quantify the relative effect of modifiable factors, such as time of vaccination.

Vaccine Hesitancy: Contemporary Issues and Historical Background

Vaccination, despite being recognized as one of the most effective primary public health measures, is viewed as unsafe and unnecessary by an increasing number of individuals. Anxiety about vaccines and vaccination programs leading to vaccine hesitancy results from a complex mix of social and political influences, cultural and religious beliefs, the availability of and ability to interpret health and scientific information, and personal and population experiences of health systems and government policies. Vaccine hesitancy is becoming a serious threat to vaccination programs, and was identified as one of the World Health Organization’s top ten global health threats in 2019. The negative impact of anti-vaccination movements is frequently cited as one of the major reasons for rising vaccine hesitancy amongst the general public world-wide. This review discusses the various issues surrounding vaccine hesitancy and the anti-vaccine movement, starting with the definitions of vaccine hesitancy and the anti-vaccine movement in their early history and in the modern era, before discussing the key drivers of vaccine hesitancy, particularly across different regions of the world, with a focus on various countries with low-, middle-, or high-income economies with different socio-economic populations. The review concludes with the impact of vaccine hesitancy on herd immunity and social, psychological, and public health measures to counter vaccine hesitancy.

Common adverse events following immunization with the COVID-19 comirnaty vaccine (Pfizer-BioNTech) among adult population in Hanoi, Vietnam, 2021

Rationale

To prevent and control the COVID-19 pandemic, the biggest immunization campaign in history had been deployed worldwide. Therefore, it is important to inform the adverse events following immunization (AEFI) to populations.

Objectives

To prevent vaccine hesitancy, this study focused on finding the common AEFI with the COVID-19 Comirnaty vaccine (Pfizer-BioNTech) among participants aged 18 and above and related factors in Hanoi, Vietnam.

Methods

A cross-sectional study was carried out to collect participants’ data and AEFI after being vaccinated at Hanoi Medical University, Vietnam, in 2021. Logistic regression was utilized for analyzing the correlated factors of AEFI.

Results

We recruited a random sample of 820 participants who received both basic doses of Pfizer vaccine in September and October 2021. The proportion of AEFI after the first dose, second dose, and both doses of Pfizer vaccine was 24.4%, 64.2%, and 18.5%, respectively. AEFI mostly appeared within 1 day and lasted for 1 to 2 days. The AEFI were more common in females (OR=1.7; 95%CI=1.25–2.29) and younger age groups (OR=1.9; 95%CI=1.37–2.58). History of allergy, allergic diseases, chronic diseases, and occupations were not statistically significant with AEFI.

Conclusion

Our findings indicated that the COVID-19 Comirnaty vaccine is safe to be injected. Gender and age group are important factors influencing AEFI.

Negative COVID-19 Vaccine Information on Twitter: Content Analysis

Background

Social media platforms, such as Facebook, Instagram, Twitter, and YouTube, have a role in spreading anti-vaccine opinion and misinformation. Vaccines have been an important component of managing the COVID-19 pandemic, so content that discourages vaccination is generally seen as a concern to public health. However, not all negative information about vaccines is explicitly anti-vaccine, and some of it may be an important part of open communication between public health experts and the community.

Objective

This research aimed to determine the frequency of negative COVID-19 vaccine information on Twitter in the first 4 months of 2021.

Methods

We manually coded 7306 tweets sampled from a large sampling frame of tweets related to COVID-19 and vaccination collected in early 2021. We also coded the geographic location and mentions of specific vaccine producers. We compared the prevalence of anti-vaccine and negative vaccine information over time by author type, geography (United States, United Kingdom, and Canada), and vaccine developer.

Results

We found that 1.8% (131/7306) of tweets were anti-vaccine, but 21% (1533/7306) contained negative vaccine information. The media and government were common sources of negative vaccine information but not anti-vaccine content. Twitter users from the United States generated the plurality of negative vaccine information; however, Twitter users in the United Kingdom were more likely to generate negative vaccine information. Negative vaccine information related to the Oxford/AstraZeneca vaccine was the most common, particularly in March and April 2021.

Conclusions

Overall, the volume of explicit anti-vaccine content on Twitter was small, but negative vaccine information was relatively common and authored by a breadth of Twitter users (including government, medical, and media sources). Negative vaccine information should be distinguished from anti-vaccine content, and its presence on social media could be promoted as evidence of an effective communication system that is honest about the potential negative effects of vaccines while promoting the overall health benefits. However, this content could still contribute to vaccine hesitancy if it is not properly contextualized.

Application of behavioral economics for understanding health behaviors among adolescents and young adults

PURPOSE OF REVIEW

Behavioral economics (BE) concepts have become well studied tools in addressing patient issues, such as weight loss, smoking cessation, and medication adherence. Although predominantly studied in adult populations, emerging literature has shown BE's utility for adolescent/young adult (AYA) populations, offering a practical framework to safeguard AYA health and influence healthy decision making.

RECENT FINDINGS

We identified substantive areas in which BE concepts have been applied in AYA populations (e.g., substance use) and outline how these concepts have been used as a tool to identify individuals at risk for poor outcomes and to leverage behavioral insights to improve health behaviors.

SUMMARY

BE research holds significant promise as a tool for clinicians and researchers to encourage healthy decision making in AYA populations. Yet, there are opportunities for BE research to expand further into current trends impacting adolescent health, such as electronic nicotine delivery systems, social media apps, and coronavirus disease 2019 vaccinations. Furthermore, the full degree of BE utility remains to be explored, as few studies demonstrate the translation of associative findings into direct interventions. Additional work is needed to formalize BE techniques into best practices that clinicians can implement in their daily practice.

Vaccine Hesitancy and Cognitive Biases: Evidence for tailored communication with parents

•

The model to analyse vaccine hesitancy should include the evaluation of cognitive biases.

•

Communication interventions should be tailored based on the drivers of parents’ choice.

•

Conspiracy mentality and risk propension correlate with the vaccine hesitancy.

Background

Vaccine hesitancy (VH) remains worldwide a reason of concern. Most of the vaccination education strategies followed a “fact-based” approach, based on the assumption that decision making is a rational process, without considering the influence of cognitive biases and heuristics. Our study aimed at identifying factors involved in the parents’ vaccination choice to inform and shape communication interventions.

Methods

We conducted an online national survey among parents between November 2020 and April 2021. The questionnaire consisted of 42 items organised in 4 parts: (1) personal information, (2) cognitive biases and risk propension, (3) Analytic Thinking (Cognitive Reflection Test), (4) conspiracy mentality, health literacy, and VH. Exploratory factor analysis was conducted to identify latent variables underlying the 19 items related to the 6 cognitive biases. Factors were categorised in quintiles and the corresponding pseudo-continuous variables used as predictors of the VH. Logistic regression model was applied to assess the association of the VH with factors, conspiracy mentality and risk propension. We adjusted for age, gender, economic status, and education levels.

Results

The study included 939 parents, 764 women (81.4%), 69.8% had a degree or higher level of education. Considering cognitive biases, four factors explaining 54% of the total variance were identified and characterised as: fear of the side effects of vaccines (scepticism factor); carelessness of the risk and consequences of infections (denial factor); optimistic attitude (optimistic bias factor); preference for natural products (naturalness bias factor). All factors were positively associated to VH (p < 0.001) as were conspiracy mentality (p = 0.007) and risk propension (p = 0.002).

Conclusions

This study confirmed the need to amplify the model used to analyse the VH considering cognitive biases as important factor affecting the parents’ decision making. These results may be useful to design personalised communication interventions regarding vaccines and vaccination.

Impact of COVID-19 vaccine-associated side effects on health care worker absenteeism and future booster vaccination

BACKGROUND

Short-term side effects related to mRNA vaccines against SARS-CoV-2 are frequent and bothersome, with the potential to disrupt work duties and impact future vaccine decision-making.

OBJECTIVE

To identify factors more likely to lead to vaccine-associated work disruption, employee absenteeism, and future vaccine reluctance among healthcare workers (HCWs).

HYPOTHESIS

Side effects related to COVID vaccination: 1- frequently disrupt HCW duties, 2- result in a significant proportion of HCW absenteeism, 3- contribute to uncertainty about future booster vaccination, 4- vary based on certain demographic, socioeconomic, occupational, and vaccine-related factors.

METHODS

Using an anonymous, voluntary electronic survey, we obtained responses from a large, heterogeneous sample of COVID-19-vaccinated HCWs in two healthcare systems in Southern California. Descriptive statistics and regression models were utilized to evaluate the research questions.

RESULTS

Among 2,103 vaccinated HCWs, 579 (27.5%) reported that vaccine-related symptoms disrupted their professional responsibilities, and 380 (18.1%) missed work as a result. Independent predictors for absenteeism included experiencing generalized and work-disruptive symptoms, and receiving the Moderna vaccine [OR = 1.77 (95% CI = 1.33 - 2.36), p < 0.001]. Physicians were less likely to miss work due to side effects (6.7% vs 21.2% for all other HCWs, p < 0.001). Independent predictors of reluctance toward future booster vaccination included lower education level, younger age, having received the Moderna vaccine, and missing work due to vaccine-related symptoms.

CONCLUSION

Symptoms related to mRNA vaccinations against SARS-CoV-2 may frequently disrupt work duties, lead to absenteeism, and impact future vaccine decision-making. This may be more common in Moderna recipients and less likely among physicians. Accordingly, health employers should schedule future booster vaccination cycles to minimize loss of work productivity.

Fear of COVID-19 predicts vaccination willingness 14 months later

Vaccines are an important tool for governments and health agencies to contain and curb the Coronavirus Disease-19 (COVID-19) pandemic. However, despite their effectiveness and safeness, a substantial portion of the population worldwide is hesitant to get vaccinated. In the current study, we examined whether fear of COVID-19 predicts vaccination willingness. In a longitudinal study (N = 938), fear for COVID-19 was assessed in April 2020 and vaccination willingness was measured in June 2021. Approximately 11% of our sample indicated that they were not willing to get vaccinated. Results of a logistic regression showed that increased fear of COVID-19 predicts vaccination willingness 14 months later, even when controlling for several anxious personality traits, infection control perceptions, risks for loved ones, self-rated health, previous infection, media use, and demographic variables. These results show that fear of COVID-19 is a relevant construct to consider for predicting and possibly influencing vaccination willingness. Nonetheless, sensitivity and specificity of fear of COVID-19 to predict vaccination willingness were quite low and only became slightly better when fear of COVID-19 was measured concurrently. This indicates that other potential factors, such as perceived risks of the vaccines, probably also play a role in explaining vaccination willingness.

The role of social media in promoting vaccine hesitancy

PURPOSE OF REVIEW

To offer: (1) Insight into the antivaccine movement's use of social media negatively impacting vaccine hesitancy and disease outbreaks, (2) Examples via case observations, and (3) Selected resources to combat vaccine hesitancy.

RECENT FINDINGS

For the past 25 years, daily social media usage has risen continually, allowing information to spread widely to a reading/listening/viewing audience via mostly unvetted social media sites. During a pandemic/epidemic (e.g., coronavirus disease 2019 pandemic), an overabundance of information from many sources, including social media, has led to what is now termed as an 'infodemic'. Infodemics arise from overwhelming amounts of both correct and incorrect information from experts and nonexperts alike. Differentiating correct from incorrect information is difficult for social media users who can be swayed by nonscientific 'influencers' or fear-mongering more than by vetted expert scientific information. Consequently, vaccine misinformation is steadily increasing via social media, the use of which is often believed to be associated with vaccine hesitancy. Stopping the spread of misinformation has been a difficult task.

SUMMARY

Vaccine misinformation on social media has been detrimental to public health. Vaccine advocates must increase the use of social media to the advantage of public health in the persistent struggle against vaccine hesitancy/refusal.

Understanding the phases of vaccine hesitancy during the COVID-19 pandemic

Vaccine hesitancy is an important feature of every vaccination and COVID-19 vaccination is not an exception. During the COVID-19 pandemic, vaccine hesitancy has exhibited different phases and has shown both temporal and spatial variation in these phases. This has likely arisen due to varied socio-behavioural characteristics of humans and their response towards COVID 19 pandemic and its vaccination strategies. This commentary highlights that there are multiple phases of vaccine hesitancy: Vaccine Eagerness, Vaccine Ignorance, Vaccine Resistance, Vaccine Confidence, Vaccine Complacency and Vaccine Apathy. Though the phases seem to be sequential, they may co-exist at the same time in different regions and at different times in the same region. This may be attributed to several factors influencing the phases of vaccine hesitancy. The complexities of the societal reactions need to be understood in full to be addressed better. There is a dire need of different strategies of communication to deal with the various nuances of all of the phases. To address of vaccine hesitancy, an understanding of the societal reactions leading to various phases of vaccine hesitancy is of utmost importance.

Association of SARS-CoV-2 Vaccinations with SARS-CoV-2 Infections, ICU Admissions and Deaths in Greece

The available coronavirus disease 2019 (COVID-19) vaccines have shown their effectiveness in clinical trials. We aimed to assess the real-world effects of SARS-CoV-2 vaccinations in Greece. We combined national data on vaccinations, SARS-CoV-2 cases, COVID-19-related ICU admissions and COVID-19-related deaths. We observed 3,367,673 vaccinations (30.68% of the Greek population), 278,821 SARS-CoV-2 infections and 7401 COVID-19-related deaths. The vaccination rate significantly increased from week 2 to week 6 by 85.70%, and from week 7 to 25 by 15.65%. The weekly mean of SARS-CoV-2 cases, COVID-19 ICU patients and COVID-19 deaths markedly declined as vaccination coverage accumulated. The rate of SARS-CoV-2 cases increased significantly from week 2 to week 13 by 16.15%, while from weeks 14–25 the rate decreased significantly by 13.50%. The rate of COVID-19-related ICU admissions decreased significantly by 7.41% from week 2 to week 4, increased significantly by 17.22% from weeks 5–11, then decreased significantly from weeks 17–20, by 11.99%, and from weeks 21–25, by 16.77%. The rate of COVID-19-related deaths increased significantly from week 2 to week 15 by 12.08% and decreased significantly by 16.58% from weeks 16–25. The data from this nationwide observational study underline the beneficial impact of the national vaccination campaign in Greece, which may offer control of the SARS-CoV-2 pandemic.

Efficacy of a brief, altruism-eliciting video intervention in enhancing COVID-19 vaccination intentions amongst a population-based sample of younger adults: Randomized controlled trial (Preprint)

Background

High COVID-19 vaccine uptake is crucial to containing the pandemic and reducing hospitalizations and deaths. Younger adults (aged 20-39 years) have demonstrated lower levels of vaccine uptake compared to older adults, while being more likely to transmit the virus due to a higher number of social contacts. Consequently, this age group has been identified by public health authorities as a key target for vaccine uptake. Previous research has demonstrated that altruistic messaging and motivation is associated with vaccine acceptance.

Objective

This study had 2 objectives: (1) to evaluate the within-group efficacy of an altruism-eliciting short, animated video intervention in increasing COVID-19 vaccination intentions amongst unvaccinated Canadian younger adults and (2) to examine the video’s efficacy compared to a text-based intervention focused exclusively on non-vaccine-related COVID-19 preventive health measures.

Methods

Using a web-based survey in a pre-post randomized control trial (RCT) design, we recruited Canadians aged 20-39 years who were not yet vaccinated against COVID-19 and randomized them in a 1:1 ratio to receive either the video intervention or an active text control. The video intervention was developed by our team in collaboration with a digital media company. The measurement of COVID-19 vaccination intentions before and after completing their assigned intervention was informed by the multistage Precaution Adoption Process Model (PAPM). The McNemar chi-square test was performed to evaluate within-group changes of vaccine intentions. Exact tests of symmetry using pairwise McNemar tests were applied to evaluate changes in multistaged intentions. Between-group vaccine intentions were assessed using the Pearson chi-square test postintervention.

Results

Analyses were performed on 1373 participants (n=686, 50%, in the video arm, n=687, 50%, in the text arm). Within-group results for the video intervention arm showed that there was a significant change in the intention to receive the vaccine (χ²₁=20.55, P<.001). The between-group difference in postintervention intentions (χ²₃=1.70, P=.64) was not significant. When administered the video intervention, we found that participants who had not thought about or were undecided about receiving a COVID-19 vaccine were more amenable to change than participants who had already decided not to vaccinate.

Conclusions

Although the video intervention was limited in its effect on those who had firmly decided not to vaccinate, our study demonstrates that prosocial and altruistic messages could increase COVID-19 vaccine uptake, especially when targeted to younger adults who are undecided or unengaged regarding vaccination. This might indicate that altruistic messaging provides a “push” for those who are tentative toward, or removed from, the decision to receive the vaccine. The results of our study could also be applied to more current COVID-19 vaccination recommendations (eg, booster shots) and for other vaccine-preventable diseases.

Trial Registration

ClinicalTrials.gov NCT04960228; https://clinicaltrials.gov/ct2/show/NCT04960228

Impact of Local and Demographic Factors on Early COVID-19 Vaccine Hesitancy among Health Care Workers in New York City Public Hospitals

Despite the development of several effective vaccines, SARS-CoV-2 continues to spread, causing serious illness among the unvaccinated. Healthcare professionals are trusted sources of information about vaccination, and therefore understanding the attitudes and beliefs of healthcare professionals regarding the vaccines is of utmost importance. We conducted a survey-based study to understand the factors affecting COVID-19 vaccine attitudes among health care professionals in NYC Health and Hospitals, at a time when the vaccine was new, and received 3759 responses. Machine learning and chi-square analyses were applied to determine the factors most predictive of vaccine hesitancy. Demographic factors, education, role at the hospital, perceptions of the pandemic itself, and location of work and residence were all found to significantly contribute to vaccine attitudes. Location of residence was examined for both borough and neighborhood, and was found to have a significant impact on vaccine receptivity. Interestingly, this borough-level data did not correspond to the number or severity of cases in the respective boroughs, indicating that local social or other influences likely have a substantial impact. Local and demographic factors should be strongly considered when preparing pro-vaccine messages or campaigns.

COVID-19 vaccine literacy in patients with systemic autoimmune diseases

COVID-19 related infodemic is a threat to the successful COVID-19 vaccination campaigns. This might be especially apparent for patients with autoimmune diseases since there is no data available about the balance between benefits and risks of the newly developed COVID-19 vaccines in this population. We aim (i) to evaluate vaccine literacy skills in a population of patients with systemic autoimmune diseases, (ii) to examine the potential associations between vaccine literacy skills and sociodemographic characteristics and (iii) to analyze the relationships between attitudes, perceptions and beliefs about current vaccinations and vaccine literacy skills and sociodemographic characteristics. A cross-sectional study was conducted among 319 patients with systemic autoimmune diseases (92% females; 49.5% of patients in the 31-50 years age category). The vaccine literacy levels were determined using the Health Literacy about Vaccination in adulthood in Italian (HLVa-IT). Sociodemographic characteristics including gender, age, country and area of residence, civil status, socioeconomic status, educational attainment and occupational status were evaluated. The mean vaccine literacy functional and interactive-critical scores were 2.59 ± 0.74 and 3.07 ± 0.60, respectively. The vaccine literacy interactive-critical score was higher in females than in males (p = 0.048). Interactive-critical scores were associated with the area of residence, civil status and socioeconomic status, with the highest score in urban area of ≥ 100.000 inhabitants (p = 0.045), in widow patients (p = 0.023) and in patients with high socioeconomic status (p = 0.018). Significant differences were observed between the different education levels, for both the functional and the interactive-critical scores (p = 0.002 and p < 0.001, respectively), the highest score was observed in patients who completed a university degree. The level of vaccine literacy for functional and interactive-critical scales were medium. Area of residence, civil status and socioeconomic status represented determinants of vaccine literacy interactive-critical scale. Educational attainment also contributes to vaccine literacy functional scale. Insight into these factors is required to ensure an optimal vaccine literacy level in patients with autoimmune diseases.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s12144-022-02713-y.