Monetary incentives increase COVID-19 vaccinations

Effectiveness of financial incentives on influenza vaccination among older adults in China: a randomized clinical trial

OBJECTIVES

To investigate the short-term and long-term effectiveness of different levels of financial incentives on increasing the willingness to vaccinate and vaccine uptake.

METHODS

A randomized controlled trial was conducted to investigate the effectiveness of financial incentives of three groups with monetary incentives (CNY 20, CNY 40, and CNY 60; 1 CNY = 0.13 EUR) vs. a control group-CNY 0-on influenza vaccine uptake among 720 older adults (≥60 years) in Beijing, China. The primary outcome was vaccine uptake, and the secondary outcomes were intention to vaccinate and length of time to immunization.

RESULTS

Financial incentive significantly promoted higher intention to influenza vaccination (120/178 [67.42%] vs. 442/542 [81.55%]; Relative Risk [RR], 1.21; 95% CI, 1.02-1.42) and higher vaccination participation (74/178 [41.57%] vs. 316/542 [58.30%]; RR, 1.39; 95% CI, 1.10-1.75). CNY 60 had the largest impact on the intention to vaccinate (15.00% vs. 13.48% and 13.90%) and vaccination uptake (19.42% vs. 14.05% and 16.67%) compared with CNY 20 and CNY 40. Time to vaccination was significantly lower among participants receiving incentives than those without ([37.21 days; 95% CI, 34.33-39.99] vs. [48.27 days; 95% CI, 43.47-53.07]; Hazard Ratio [HR] 1.57, 95% CI 1.22-2.03). We found no long-term influence of financial incentives on vaccination decisions in the following year (217/542, 40.04% vs. 65/178, 36.52%; RR 1.08, 95% CI 0.82-1.42).

DISCUSSION

Our study suggests that modest financial incentives will boost short-term influenza vaccination rates and shorten the length of time to immunization in China. No one single-time financial incentive had a long-term effect on future vaccination behaviours or helped establish regular vaccination behaviours.

Simple economics of vaccination: public policies and incentives

This paper focuses on the economics of vaccination and, more specifically, analyzes the vaccination decision of individuals using a game-theoretic model combined with an epidemiological SIR model that reproduces the infection dynamics of a generic disease. We characterize the equilibrium individual vaccination rate, and we show that it is below the rate compatible with herd immunity due to the existence of externalities that individuals do not internalize when they decide on vaccination. In addition, we analyze three public policies consisting of informational campaigns to reduce the disutility of vaccination, monetary payments to vaccinated individuals and measures to increase the disutility of non-vaccination. If the public authority uses only one type of policy, herd immunity is not necessarily achieved unless monetary incentives are used. When the public authority is not limited to use only one policy, we find that the optimal public policy should consist only of informational campaigns if they are sufficiently effective, or a combination of informational campaigns and monetary incentives otherwise. Surprisingly, the requirement of vaccine passports or other restrictions on the non-vaccinated are not desirable.

Guaranteed Cash Incentives Boosted COVID-19 Vaccinations Of Young Adults: Evidence From West Virginia

Guaranteed small cash incentives were widely employed by policy makers during the COVID-19 vaccination campaign, but the impact of these programs has been largely understudied. We were the first to exploit a statewide natural experiment of one such program implemented in West Virginia in 2021 that provided a $100 incentive to fully vaccinated adults ages 16-35. Using individual-level data from the Census Bureau's Household Pulse Survey, we isolated the policy effect through a difference-in-discontinuities design that exploited the discontinuity in incentive eligibility at age thirty-five. We found that the $100 incentive was associated with a robust increase in the proportion of people ever vaccinated against COVID-19 and the proportion who completed or intended to complete the primary series of COVID-19 vaccines. The policy effects were also likely to be more pronounced among people with low incomes, those who were unemployed, and those with no prior COVID-19 infection. The guaranteed cash incentive program may have created more equitable access to vaccines for disadvantaged populations. Additional outreach may also be needed, especially to unvaccinated people with prior COVID-19 infections.

An experimental test of whether financial incentives constitute undue inducement in decision-making

Around the world, laws limit the incentives that can be paid for transactions such as human research participation, egg donation or gestational surrogacy. A key reason is concerns about 'undue inducement'-the influential but empirically untested hypothesis that incentives can cause harm by distorting individual decision-making. Here I present two experiments (n = 671 and n = 406), including one based on a highly visceral transaction (eating insects). Incentives caused biased information search-participants offered a higher incentive to comply more often sought encouragement to do so. However, I demonstrate theoretically that such behaviour does not prove that incentives have harmful effects; it is consistent with Bayesian rationality. Empirically, although a substantial minority of participants made bad decisions, incentives did not magnify them in a way that would suggest allowing a transaction but capping incentives. Under the conditions of this experiment, there was no evidence that higher incentives could undermine welfare for transactions that are permissible at low incentives.

Compliance in the public versus the private realm: Economic preferences, institutional trust and COVID-19 health behaviors

To what extent do economic preferences and institutional trust predict compliance with physical distancing rules during the COVID-19 pandemic? We reexamine this question by introducing the theoretical and empirical distinction between individual health behaviors in the public and in the private domain (e.g., keeping a distance from strangers vs. abstaining from private gatherings with friends). Using structural equation modeling to analyze survey data from Germany's second wave of the pandemic (N = 3350), we reveal the following major differences between compliance in both domains: Social preferences, especially (positive) reciprocity, play an essential role in predicting compliance in the public domain but are barely relevant in the private domain. Conversely, individuals' degree of trust in the national government matters predominantly for increasing compliance in the private domain. The clearly strongest predictor in this domain is the perception pandemic-related threats. Our findings encourage tailoring communication strategies to either domain-specific circumstances or factors common across domains. Tailored communication may also help promote compliance with other health-related regulatory policies beyond COVID-19.

Motivators and Demotivators for COVID-19 Vaccination Based on Co-Occurrence Networks of Verbal Reasons for Vaccination Acceptance and Resistance: Repetitive Cross-Sectional Surveys and Network Analysis

BACKGROUND

Vaccine hesitancy is complex and multifaced. People may accept or reject a vaccine due to multiple and interconnected reasons, with some reasons being more salient in influencing vaccine acceptance or resistance and hence the most important intervention targets for addressing vaccine hesitancy.

OBJECTIVE

This study was aimed at assessing the connections and relative importance of motivators and demotivators for COVID-19 vaccination in Hong Kong based on co-occurrence networks of verbal reasons for vaccination acceptance and resistance from repetitive cross-sectional surveys.

METHODS

We conducted a series of random digit dialing telephone surveys to examine COVID-19 vaccine hesitancy among general Hong Kong adults between March 2021 and July 2022. A total of 5559 and 982 participants provided verbal reasons for accepting and resisting (rejecting or hesitating) a COVID-19 vaccine, respectively. The verbal reasons were initially coded to generate categories of motivators and demotivators for COVID-19 vaccination using a bottom-up approach. Then, all the generated codes were mapped onto the 5C model of vaccine hesitancy. On the basis of the identified reasons, we conducted a co-occurrence network analysis to understand how motivating or demotivating reasons were comentioned to shape people's vaccination decisions. Each reason's eigenvector centrality was calculated to quantify their relative importance in the network. Analyses were also stratified by age group.

RESULTS

The co-occurrence network analysis found that the perception of personal risk to the disease (egicentrality=0.80) and the social responsibility to protect others (egicentrality=0.58) were the most important comentioned reasons that motivate COVID-19 vaccination, while lack of vaccine confidence (egicentrality=0.89) and complacency (perceived low disease risk and low importance of vaccination; egicentrality=0.45) were the most important comentioned reasons that demotivate COVID-19 vaccination. For older people aged ≥65 years, protecting others was a more important motivator (egicentrality=0.57), while the concern about poor health status was a more important demotivator (egicentrality=0.42); for young people aged 18 to 24 years, recovering life normalcy (egicentrality=0.20) and vaccine mandates (egicentrality=0.26) were the more important motivators, while complacency (egicentrality=0.77) was a more important demotivator for COVID-19 vaccination uptake.

CONCLUSIONS

When disease risk is perceived to be high, promoting social responsibility to protect others is more important for boosting vaccination acceptance. However, when disease risk is perceived to be low and complacency exists, fostering confidence in vaccines to address vaccine hesitancy becomes more important. Interventions for promoting vaccination acceptance and reducing vaccine hesitancy should be tailored by age.

Vaccination as personal public good provision

Vaccination against infectious diseases has both private and public benefits. We study whether social preferences-concerns for the well-being of other people-are associated with one's decision regarding vaccination. We measure these social preferences for 549 online subjects with a public-good game and an altruism game. To the extent that one gets vaccinated out of concern for the health of others, contribution in the public-good game is analogous to an individual's decision to obtain vaccination, while our altruism game provides a different measure of altruism, equity, and efficiency concerns. We proxy vaccine demand with how quickly a representative individual voluntarily took the initial vaccination for COVID-19 (after the vaccine was widely available). We collect COVID-19 vaccination history separately from the games to avoid experimenter-demand effects. We find a strong result: Contribution in the public-good game is associated with greater demand to voluntarily receive a first dose, and thus also to vaccinate earlier. Compared to a subject who contributes nothing, one who contributes the maximum ($4) is 58% more likely to obtain a first dose voluntarily in the four-month period that we study (April through August 2021). In short, people who are more pro-social are more likely to take a voluntary COVID-19 vaccination. Behavior in our altruism game does not predict vaccination. We recommend further research on the use of pro-social preferences to help motivate individuals to vaccinate for other transmissible diseases, such as the flu and HPV.

Regional variations in vaccination against COVID-19 in Germany

Vaccination willingness against COVID-19 is generally perceived as low. Moreover, there is large heterogeneity across and within countries. As a whole, Germany has average vaccination rates compared to other industrialized countries. However, vaccination rates in the 16 different German federal states differ by more than 20 percentage points. We describe variation in vaccination rates on the level of the 400 German counties using data on all vaccinations carried out until December 2022. Around 52-72% of that variation can be explained by regional differences in demographic characteristics, housing, education and political party preferences. We find indications that the remaining part may be due to differences in soft factors such as risk aversion, trust in the German government, trust in science, and beliefs in conspiracy theories regarding the origins of the Corona virus. We conclude that improving the trust in science and the fight against conspiracy theories may possibly be effective tools to improve vaccination rates and effectively fight pandemics.

Effects of COVID-19 vaccine safety framing on parental reactions

As a major concern shared by parents globally, COVID-19 vaccine safety is typically being messaged to the public in a negative frame in many countries. However, whether the COVID-19 vaccine safety framing have an effect on parents when vaccinating their children is unclear. Here we implement an online survey with a convenience sample of 3,861 parents living in mainland China, all over 18 years old and with at least one child under 18. The parents were randomly assigned to receive information about COVID-19 vaccine safety in either a negative frame (incidence of side effects) or a positive frame (the inverse incidence of side effects), to compare parental reactions to a range of questions about communication, risk perception, trust, involvement and behavioral intention. We found that parents were more likely to regard vaccine safety as relevant to policy support and as a higher priority for government when receiving positively framed information (p = 0.002). For some specific subgroups, parents in positive framing group showed lower risk perception and higher trust (p<0.05). This suggests that positive framing of COVID-19 vaccine safety messages show more effective performance than negative framing in terms of involvement, as well as trust and risk perception in specific subgroups, which may lead to a reflection on whether to adjust the current widespread use of negative framing. Our findings inform how governments and health care workers strategically choose the framing design of COVID-19 vaccine safety information, and have important implications for promoting COVID-19 vaccination in children in the future.

The causal effect of a health treatment on beliefs, stated preferences and memories

The paper estimates the causal effect of a health treatment on patients' beliefs, preferences and memories about the treatment. It exploits a natural experiment which occurred in the United Kingdom during the COVID-19 vaccination campaign. UK residents could choose to opt into the vaccination program, but not which vaccine they received. The assignment to a vaccine offered little objective information for learning about its qualities, but triggered strong psychological demand for reassuring beliefs. We surveyed a sample of UK residents about their beliefs on the different COVID-19 vaccines before and after receiving their jab. Before vaccination, individuals exhibit similar prior beliefs and stated preferences about the different vaccines. After vaccination, however, they update their beliefs overly optimistically about the safety and effectiveness of the vaccine they received, state that they would have chosen it if they could, and have distorted memories about their past beliefs. These results cannot be explained by conventional experience effects. At the aggregated level, they show that random assignment to a health treatment predicts a polarization of opinions about its quality. At the individual level, these findings provide evidence in line with the predictions of motivated beliefs and over-inference from weak signals in a real-world health setting.

Vaccine-skeptic physicians and patient vaccination decisions

What is the role of general practitioners (GPs) in supporting or hindering public health efforts? We investigate the influence of vaccine-skeptic GPs on their patients' decisions to get a COVID-19 vaccination. We identify vaccine-skeptic GPs from the signatories of an open letter in which 199 Austrian physicians expressed their skepticism about COVID-19 vaccines. We examine small rural municipalities where patients choose a GP primarily based on geographic proximity. These vaccine-skeptic GPs reduced the vaccination rate by 5.6 percentage points. This estimate implies that they discouraged 7.9% of the vaccinable population. The effect appears to stem from discouragement rather than rationing vaccine access.

The motivating effect of monetary over psychological incentives is stronger in WEIRD cultures

Motivating effortful behaviour is a problem employers, governments and nonprofits face globally. However, most studies on motivation are done in Western, educated, industrialized, rich and democratic (WEIRD) cultures. We compared how hard people in six countries worked in response to monetary incentives versus psychological motivators, such as competing with or helping others. The advantage money had over psychological interventions was larger in the United States and the United Kingdom than in China, India, Mexico and South Africa (N = 8,133). In our last study, we randomly assigned cultural frames through language in bilingual Facebook users in India (N = 2,065). Money increased effort over a psychological treatment by 27% in Hindi and 52% in English. These findings contradict the standard economic intuition that people from poorer countries should be more driven by money. Instead, they suggest that the market mentality of exchanging time and effort for material benefits is most prominent in WEIRD cultures.

Last-mile delivery increases vaccine uptake in Sierra Leone

Less than 30% of people in Africa received a dose of the COVID-19 vaccine even 18 months after vaccine development1. Here, motivated by the observation that residents of remote, rural areas of Sierra Leone faced severe access difficulties2, we conducted an intervention with last-mile delivery of doses and health professionals to the most inaccessible areas, along with community mobilization. A cluster randomized controlled trial in 150 communities showed that this intervention with mobile vaccination teams increased the immunization rate by about 26 percentage points within 48-72 h. Moreover, auxiliary populations visited our community vaccination points, which more than doubled the number of inoculations administered. The additional people vaccinated per intervention site translated to an implementation cost of US $33 per person vaccinated. Transportation to reach remote villages accounted for a large share of total intervention costs. Therefore, bundling multiple maternal and child health interventions in the same visit would further reduce costs per person treated. Current research on vaccine delivery maintains a large focus on individual behavioural issues such as hesitancy. Our study demonstrates that prioritizing mobile services to overcome access difficulties faced by remote populations in developing countries can generate increased returns in terms of uptake of health services3.

Chiral Nanomaterials for Cancer Vaccines

Chirality is a fundamental characteristic of living organisms and is commonly observed at the biomolecule, cellular, and tissue levels. Chiral nanomaterials play an irreplaceable role in nanomedicine and nanobiology because of their unique enantioselectivity with biological components. Here, research progress relating to chiral nanomaterials in the field of vaccines is reviewed, including antigen presenting systems, immune adjuvants, and cancer vaccines. First, the common synthesis methods are outlined for different types of chiral nanomaterials, as well as their chiral sources, optical properties, and potential biological applications. Then, the application of chiral nanomaterials are discussed in the field of vaccines with reference to the promotion of antigen presentation and activation of the immune system for tumor immunotherapy. Finally, the current obstacles and future research directions of chiral nanomaterials are revealed with regard to regulating the immune system.

Surname order and revaccination intentions during the COVID-19 pandemic

Teachers in Japanese schools employ alphabetical surname lists that call students sooner, with surnames appearing early on these lists. We conducted Internet surveys nearly every month from March 2020 to September 2022 with the same participants, wherein we asked participants where the alphabetical columns of their childhood and adult surnames were located. We aimed to identify how surname order is important for the formation of noncognitive skills. During the data collection period, the COVID-19 vaccines became available; Japanese people could receive their third dose starting in December 2021. The 19th wave of the survey was conducted in January 2022. Therefore, to examine how a surname's alphabetical order could influence intention to revaccinate, we used a subsample of data from December 2021 to September 2022. The major findings were as follows. Women with early surnames had an approximately 4% stronger likelihood of having such intentions than men with early surnames. Early name order was more strongly correlated with revaccination intention among women than among men. The surname effect for women was larger when a mixed-gender list was used compared with when it was not used. This effect was only observed for childhood surnames and not for adult surnames.

Mobile vaccination units substantially increase COVID-19 vaccinations: evidence from a randomized controlled trial

BACKGROUND

Governments around the world used mobile vaccination units (MVUs) to increase COVID-19 vaccine uptake, but the causal effect of MVUs has not yet been evaluated.

METHODS

In a randomized controlled trial (RCT) with 20 Swiss communities (10 treatment, 10 control) in August 2021, MVUs were sent to treatment communities for 4 hours on a single day. The experimental sample comprises 20 414 adults who were unvaccinated against COVID-19 at this point. The researchers designed the RCT and the government introduced the idea to test the effectiveness of MVUs and was responsible for administering the vaccines.

RESULTS

The vaccination rate in the sample of the treatment group surpassed the rate in the control group by a factor of 3.4 (+9.0 percentage points) over 3 weeks. The increase was present and highly statistically significant for women, men and for all age groups. We found no evidence of cannibalization of vaccinations at other service locations.

CONCLUSIONS

The offer of MVUs is highly effective in raising vaccination rates, even at a later point in the vaccination campaign. The absence of cannibalization effects suggests that MVUs reach more people overall, not just faster.

How can we promote vaccination of the mass population?-Lessons from the COVID-19 vaccination defaults

While vaccines are pivotal in combating COVID-19, concerns about side effects and complex procedures have hindered complete vaccination. Prior studies suggest that individuals defaulted to opt-out exhibit higher COVID-19 vaccination rates compared to those in opt-in systems. However, these studies were conducted in countries with a tolerant attitude towards vaccination and default changes, targeting specific age groups, and did not address potential deterrents like the increase in cancellation rates on the day, discomfort towards changing defaults, or the possibility of the opt-out effect being a one-time occurrence. Under the hypothesis that the default nature of the COVID-19 vaccination system influences attitudes towards vaccination even in countries conservative about vaccination and default changes like in Japan, we aimed to examine the differences in the first and second dose vaccination rates, cancellation rates, and the number of complaints between the opt-in and opt-out systems for COVID-19 vaccination. An email survey was conducted in 10 cities in A Prefecture, Japan. The results showed not only higher COVID-19 vaccination rates across all comparable age groups in the opt-out group but also a notably smaller decrease in the second-dose vaccination rate compared to the opt-in group, all achieved without any complaints about the system's introduction. Consequently, it can be inferred that the potential inhibiting factors were largely overcome. Despite some limitations, such as regional specificity, the study suggests that opt-out systems might increase COVID-19 vaccination coverage without leading to significant cancellations or complaints, presenting a promising strategy to facilitate vaccination efforts.

Behavioural evidence on COVID-19 vaccine uptake

OBJECTIVES

The World Health Organization has declared that COVID-19 is no longer a public health emergency of international concern. Nevertheless, it remains a public health issue, and seasonal vaccinations, at the same time of year as influenza vaccinations, will be necessary. When the first vaccines were administered in 2020, decision-makers had to make assumptions about the best methods to communicate and administer vaccines to increase uptake. Now, a body of evidence can inform these decisions.

STUDY DESIGN

A narrative review written by three behavioural scientists who design research for policy.

METHODS

We searched the PubMed database for: (i) reviews of interventions to increase uptake of COVID-19 or influenza vaccines and (ii) empirical studies on uptake of COVID-19 and influenza vaccines. In addition, registered trials gathered by a Cochrane scoping review of interventions to increase uptake of COVID-19 vaccines were searched for updated results.

RESULTS

Results centre around two aspects of a vaccination campaign of interest to policymakers: communication and administration. Results suggest that communications highlighting the personal benefits of vaccination are likely to be more effective than those highlighting collective benefits. The efficacy of vaccination may be underestimated and stressing efficacy as a strong personal benefit may increase uptake. Keeping vaccines free, sending personalised messages, reminders and prebooked appointment times may also increase uptake.

CONCLUSIONS

There is now a body of evidence from behavioural science that suggests how vaccination campaigns for COVID-19 can be structured to increase uptake. These recommendations may be useful to policymakers considering seasonal vaccination campaigns and to researchers generating hypotheses for country-specific trials.

Assessing COVID-19 Vaccine Hesitancy and Trust in Home Health Workers in New York City: A Pilot Study

OBJECTIVE

This study aimed to identify characteristics surrounding COVID-19 vaccine hesitancy and trust in home health workers (HHWs) in New York City.

METHODS

Data were collected from HHWs through focus group sessions conducted via Zoom. We developed a facilitator guide using the 5C Scale, a validated psychometric tool for assessing vaccine hesitancy. We performed qualitative thematic analysis using a combined inductive and deductive approach.

RESULTS

Major themes that emerged included the following: conflicting information decreased vaccine confidence; individualized outreach is valued when information gathering; mandates and financial incentives may increase skepticism; low health literacy and conflict in personal relationships are barriers to acceptance; and experiencing a severe infection and fear of exposure at work increase acceptance.

CONCLUSIONS

Based on our study, personalized yet consistent messaging may be key to reaching hesitant HHWs.

Policy makers believe money motivates more than it does

To motivate contributions to public goods, should policy makers employ financial incentives like taxes, fines, subsidies, and rewards? While these are widely considered as the classic policy approach, a substantial academic literature suggests the impact of financial incentives is not always positive; they can sometimes fail or even backfire. To test whether policy makers are overly bullish about financial incentives, we asked county heads, mayors, and municipal government representatives of medium-to-large towns in Germany to predict the effects of a financial incentive on COVID-19 vaccination, and tested the exact same incentive in a field experiment involving all 41,548 inhabitants (clustered in 10,032 addresses) of the German town of Ravensburg. Whereas policy makers overwhelmingly predict that the financial incentive will increase vaccination-by 15.3 percentage points on average-the same financial incentive yielded a precisely estimated null effect on vaccination. We discuss when financial incentives are most likely to fail, and conclude that it is critical to educate policy makers on the potential pitfalls of employing financial incentives to promote contributions to public goods.

Vaccine confidence mediates the association between a pro-social pay-it-forward intervention and improved influenza vaccine uptake in China: A mediation analysis

INTRODUCTION

A Chinese clinical trial has demonstrated that a prosocial pay-it-forward intervention that offered subsidized vaccination and postcard messages effectively increased influenza vaccine uptake and vaccine confidence. This secondary analysis explored the potential mediating role of vaccine confidence on the association between a pay-it-forward intervention and influenza vaccine uptake, and how this might vary by individual annual income levels.

METHODS

Data from 300 participants (150 standard-of-care and 150 pay-it-forward participants) were included in the analysis. We conducted descriptive analysis of demographic and vaccine confidence variables. Multivariable regression and mediation analysis on interventions, vaccine confidence and vaccine uptake were conducted. A sub-group analysis was conducted to further understand whether associations between these variables vary by income levels (<=$1860 or >$1860).

RESULTS

The pay-it-forward intervention was significantly associated with greater levels of perceived influenza vaccine importance (adjusted odds ratio (aOR) = 3.60, 95 %CI: 1.77-7.32), effectiveness (aOR = 3.37, 95 %CI: 1.75-6.52) and safety (aOR = 2.20, 95 %CI: 1.17-4.15). Greater perceived influenza vaccine importance was associated with increased vaccine uptake (aOR = 8.51, 95 %CI: 3.04-23.86). The indirect effect of the pay-it-forward intervention on vaccination was significant through improved perceived influenza vaccine importance (indirect effect1 = 0.07, 95 %CI: 0.02-0.11). This study further revealed that, irrespective of the individual income level, the pay-it-forward intervention was associated with increased vaccine uptake when compared to the standard-of-care approach.

CONCLUSIONS

Pay-it-forward intervention may be a promising strategy to improve influenza vaccine uptake. Perceived confidence in vaccine importance appears to be a potential mediator of the association between pay-it-forward and vaccine uptake.

A synthesis of evidence for policy from behavioural science during COVID-19

Scientific evidence regularly guides policy decisions1, with behavioural science increasingly part of this process2. In April 2020, an influential paper3 proposed 19 policy recommendations ('claims') detailing how evidence from behavioural science could contribute to efforts to reduce impacts and end the COVID-19 pandemic. Here we assess 747 pandemic-related research articles that empirically investigated those claims. We report the scale of evidence and whether evidence supports them to indicate applicability for policymaking. Two independent teams, involving 72 reviewers, found evidence for 18 of 19 claims, with both teams finding evidence supporting 16 (89%) of those 18 claims. The strongest evidence supported claims that anticipated culture, polarization and misinformation would be associated with policy effectiveness. Claims suggesting trusted leaders and positive social norms increased adherence to behavioural interventions also had strong empirical support, as did appealing to social consensus or bipartisan agreement. Targeted language in messaging yielded mixed effects and there were no effects for highlighting individual benefits or protecting others. No available evidence existed to assess any distinct differences in effects between using the terms 'physical distancing' and 'social distancing'. Analysis of 463 papers containing data showed generally large samples; 418 involved human participants with a mean of 16,848 (median of 1,699). That statistical power underscored improved suitability of behavioural science research for informing policy decisions. Furthermore, by implementing a standardized approach to evidence selection and synthesis, we amplify broader implications for advancing scientific evidence in policy formulation and prioritization.

How to increase COVID-19 vaccination among a population with persistently suboptimal vaccine uptake? Evidence from the North Macedonia mobile vaccination and public health advice caravan

Over three years since the first COVID-19 vaccine was approved, many countries still have suboptimal vaccination rates despite holding great amounts of vaccines. Overall, there is little evidence on which policies are more effective to encourage vaccination, particularly in countries where a large share of the population remains unvaccinated. In this study, we examine the effectiveness of a community-based intervention carried out in March 2022 in North Macedonia, a country with a large and persistent share of the population that remains unvaccinated. The intervention, spearheaded by the Ministry of Health and supported by the World Health Organization and UNICEF, consisted of a mobile caravan offering vaccination and public health advice to different locations across the country on different days. Results from our staggered difference-in-difference model show that the mobile vaccination caravan increased daily vaccination rates by 7.7 vaccines per 100,000 inhabitants during the three weeks after the day of the caravan visit. This corresponds to a 35 % increase with respect to pre-intervention vaccination rates. We estimate a cost-effectiveness of 25.4 US dollars (USD) per additional vaccination induced. These results point to mobile caravan vaccines as an effective and cost-effective strategy to increase COVID-19 vaccination rates, even in a context of persistently suboptimal uptake.

Reminder design and childhood vaccination coverage

A major policy concern across public vaccination programs is non-compliance. Exploiting Danish population data and three national reforms in regression discontinuity designs, we document the effects of reminders for childhood vaccination coverage. Retrospective reminders are primarily effective for families with small children and when sent out close to the recommended vaccination age. Digital and postal reminders are equally effective. Prospective reminders increase timely vaccinations in later childhood and help reaching high coverage for new vaccines in increasingly complex vaccination programs. While reminders prompt additional preventive care for focal children, we find no spillovers to other health behaviors or relatives.

Do COVID-19 Vaccination Policies Backfire? The Effects of Mandates, Vaccination Passports, and Financial Incentives on COVID-19 Vaccination

Faced with the challenges of motivating people to vaccinate, many countries have introduced policy-level interventions to encourage vaccination against COVID-19. For example, mandates were widely imposed requiring individuals to vaccinate to work and attend school, and vaccination passports required individuals to show proof of vaccination to travel and access public spaces and events. Furthermore, some countries also began offering financial incentives for getting vaccinated. One major criticism of these policies was the possibility that they would produce reactance and thus undermine voluntary vaccination. This article therefore reviews relevant empirical evidence to examine whether this is indeed the case. Specifically, we devote separate sections to reviewing and discussing the impacts of three major policies that were implemented during the COVID-19 pandemic: vaccination mandates, vaccination passports, and the provision of financial incentives. A careful analysis of the evidence provides little support that these policies backfire but instead can effectively promote vaccination at the population level. The policies are not without limitations, however, such as their inability to mobilize those that are strongly hesitant to vaccines. Finally, we discuss how policy-level interventions should be designed and implemented to address future epidemics and pandemics.

Motivating vaccination with financial incentives

Governments and organizations often offer cash payments for vaccination. How effective are such payments? A literature review shows that incentives usually increase vaccination, especially for nonhesitant populations and when using guaranteed payments. Concerns about negative unintended consequences are unsupported. We also discuss open questions and avenues for future research.

Children, vaccines, and financial incentives

Recent studies have been analyzing and measuring the efficacy of the use of financial incentives to increase the Covid-19 vaccine uptake. To the best of our knowledge, this paper is the only study available in the literature that aims to measure the effect of financial incentives on vaccine rates among children. This paper explores the effects of a specific financial incentive on parents' vaccination decisions for their children. Using data from a regional practice, where students aged 12 and older received $50 gift cards per Covid-19 vaccination dose, we use various methodologies (synthetic control, linear regression, and difference-in-differences) to approximate the effects of financial incentives on vaccine rates. Our analysis reveals that gift cards increase vaccination rates by 2.64-4.23 percentage points from a baseline rate of 38 percent, concluding that financial incentives, in conjunction with other incentives and policies, can be considered to increase the rate of vaccines for 12- to 17-year-olds.

The Role of Communication Style and External Motivators in Predicting Vaccination Experiences and Intentions: An Experimental Vignette Study

This vignette-based study examined in a sample of unvaccinated Belgian citizens (N = 1918; Mage = 45.99) how health care workers could foster reflection about and intentions to get vaccinated against COVID-19 by experimentally varying their communication style (i.e., autonomy-supportive vs. controlling) and the reference to external motivators (i.e., use of a monetary voucher or corona pass vs. the lack thereof). Each participant was randomly assigned to one of six conditions and rated a vignette in terms of anticipated autonomy satisfaction, perceived effectiveness, reflection, and vaccination intention. An autonomy-supportive, relative to a controlling, communication style predicted greater autonomy need satisfaction, which in turn related positively to perceived effectiveness, reflection, and vaccination intention. External motivators failed to generate positive effects compared to the control condition. The findings highlight the critical role of autonomy support in promoting a self-endorsed decision to get vaccinated.

Financial incentives for COVID-19 vaccines in a rural low-resource setting: a cluster-randomized trial

We implemented a clustered randomized controlled trial with 6,963 residents in six rural Ghana districts to estimate the causal impact of financial incentives on coronavirus disease 2019 (COVID-19) vaccination uptake. Villages randomly received one of four video treatment arms: a placebo, a standard health message, a high cash incentive (60 Ghana cedis) and a low cash incentive (20 Ghana cedis). For the first co-primary outcome-COVID-19 vaccination intentions-non-vaccinated participants assigned to the cash incentive treatments had an average rate of 81% (1,733 of 2,168) compared to 71% (1,895 of 2,669) for those in the placebo treatment arm. For the other co-primary outcome of self-reported vaccinations 2 months after the initial intervention, the average rate for participants in the cash treatment was 3.5% higher than for participants in the placebo treatment (95% confidence interval (CI): 0.001, 6.9; P = 0.045): 40% (602 of 1,486) versus 36.3% (672 of 1,850). We also verified vaccination status of participants: in the cash treatment arm, 36.6% (355 of 1,058) of verified participants had at least one dose of the COVID-19 vaccine compared to 30.3% (439 of 1,544) for those in the placebo-a difference of 6.3% (95% CI: 2.4, 10.2; P = 0.001). For the intention and the vaccination outcomes, the low cash incentive (20 Ghana cedis) had a larger positive effect on COVID-19 vaccine uptake than the high cash incentive (60 Ghana cedis). Trial identifier: AEARCTR-0008775 .

Role of leadership and incentive-based programs in addressing vaccine hesitancy in India

The current study goes beyond the popular 5Cs model of vaccine hesitancy to explore perceived social norms, role of leadership and the role of incentive-based intervention for improving the likelihood of vaccination, in a population-representative sample of adults in India (N = 1129). We investigated differences in socio-demographic status, perceived descriptive norms like vaccine behaviours, beliefs, experience and perceived injunctive norms like community and political leadership within the context of the COVID-19 pandemic are related to vaccination. Further, we examined the role of incentive-based intervention as a potentially salient predictor of adults' vaccine uptake. The study is based on a cross-sectional survey conducted in July-November 2021, which included questions about impacts of pandemic collected by phone call interview from adults' beneficiaries of Government free food schemes, across 11 states in India. The data include 81 % vaccinated and 19 % vaccine hesitant participants, with a higher proportion of business or self-employed (53.1 %) as vaccine hesitant. We performed the t-test to assess the variation between vaccinated and vaccine hesitant adults, and Exploratory Factor Analysis to uncover the underlying dimension of vaccine hesitancy. Subsequently, Binary Logistic Regression model probed the factors associated with likelihood of vaccination uptake. In contrast to the prevailing evidence, results demonstrated community and political leadership has significant negative impact on vaccination (p-value < 0.06, 95 % CI, 0.57-1.01). Incentive-based intervention offer a vital leverage to enhance positive attitude towards vaccination (p-value < 0.05, 95 % CI, 1.01-1.80). The results thus broadly highlight the limited role of political and community leaders in leveraging their influence on vaccination, the role of timely, accurate information, applications of telemedicine as an important tool to provide healthcare and the need for optimal design of incentive-based vaccination programs recommended by trusted sources.

COVID-19 Vaccination Among Diverse Population Groups in the Northern Governorates of Iraq

Objectives: The present study was carried out to investigate COVID-19 vaccination coverage among populations of internally displaced persons (IDPs), refugees, and host communities in northern Iraq and the related underlying factors. Methods: Through a cross-sectional study conducted in five governorates in April-May 2022, 4,564 individuals were surveyed. Data were collected through an adapted questionnaire designed to gather data on participants. Results: 4,564 subjects were included (59.55% were 19-45 years old; 54.51% male). 50.48% of the participants (51.49% of host communities, 48.83% of IDPs, and 45.87% of refugees) had been vaccinated with at least one dose of COVID-19 vaccine. 40.84% of participants (42.28% of host communities, 35.75% of IDPs, and 36.14% of refugees) had been vaccinated by two doses, and 1.56% (1.65% of host communities, 0.93% of IDPs, and 1.46% of refugees) were vaccinated with three doses. Conclusion: Sociodemographic factors including age, gender, education, occupation, and nationality could affect vaccination coverage. Moreover, higher acceptance rate of vaccination is associated with belief in vaccine safety and effectiveness and trust in the ability of the vaccine to prevent complications.

Greater Covid-19 vaccine uptake among enrollees offered health and social needs case management: Results from a randomized trial

OBJECTIVE

To investigate Covid-19 vaccination as a potential secondary public health benefit of case management for Medicaid beneficiaries with health and social needs.

DATA SOURCES AND STUDY SETTING

The CommunityConnect case management program for Medicaid beneficiaries is run by Contra Costa Health, a county safety net health system in California. Program enrollment data were merged with comprehensive county vaccination records.

STUDY DESIGN

Individuals with elevated risk of hospital and emergency department use were randomized each month to a case management intervention or usual care. Interdisciplinary case managers offered coaching, community referrals, healthcare connections, and other support based on enrollee interest and need. Using survival analysis with intent-to-treat assignment, we assessed rates of first-dose Covid-19 vaccination from December 2020 to September 2021. In exploratory sub-analyses we also examined effect heterogeneity by gender, race/ethnicity, age, and primary language.

DATA COLLECTION AND EXTRACTION METHODS

Data were extracted from county and program records as of September 2021, totaling 12,866 interventions and 25,761 control enrollments.

PRINCIPAL FINDINGS

Approximately 58% of enrollees were female and 41% were under age 35. Enrollees were 23% White, 12% Asian/Pacific Islander, 20% Black/African American, and 36% Hispanic/Latino, and 10% other/unknown. Approximately 35% of the intervention group engaged with their case manager. Approximately 56% of all intervention and control enrollees were vaccinated after 9 months of analysis time. Intervention enrollees had a higher vaccination rate compared to control enrollees (adjusted hazard ratio [aHR]: 1.06; 95% confidence interval [CI]: 1.02-1.10). In sub-analyses, the intervention was associated with stronger likelihood of vaccination among males and individuals under age 35.

CONCLUSIONS

Case management infrastructure modestly improved Covid-19 vaccine uptake in a population of Medicaid beneficiaries that over-represents social groups with barriers to early Covid-19 vaccination. Amidst mixed evidence on vaccination-specific incentives, leveraging trusted case managers and existing case management programs may be a valuable prevention strategy.

Cognitive ability, health policy, and the dynamics of COVID-19 vaccination

We examine the relationship between cognitive ability and prompt COVID-19 vaccination using individual-level data on more than 700,000 individuals in Sweden. We find a strong positive association between cognitive ability and swift vaccination, which remains even after controlling for confounding variables with a twin-design. The results suggest that the complexity of the vaccination decision may make it difficult for individuals with lower cognitive abilities to understand the benefits of vaccination. Consistent with this, we show that simplifying the vaccination decision through pre-booked vaccination appointments alleviates almost all of the inequality in vaccination behavior.

The Impact of the Macroeconomic Environment on Social Preferences: Evidence from the Global Preference Survey

The effect of social preferences, such as altruism and trust, on economic development is widely recognized. However, the reciprocal impact, i.e., how individuals experience the economic environment and how this shapes their social preferences, has remained largely under-explored. This study sheds light on this reciprocal effect, revealing an intriguing macroeconomic impact on individuals' social preferences. By harnessing the Global Preference Survey data and a non-linear regression model, our findings highlight an interesting trend: there is a discernible decrease in individuals' social preference as they experience enhanced economic conditions, and this effect is more pronounced for males. This crucial revelation underscores the importance for researchers and policymakers to take into account the prospective attenuation of social preferences in the pursuit of economic well-being.

The backfiring effects of monetary and gift incentives on Covid-19 vaccination intentions

We provide evidence that material inducements for Covid-19 vaccination may backfire. Results from a hypothetical survey experiment in China (N = 1365) show incentives of 8-125 USD reduce vaccine uptake intentions compared to simply offering vaccination for free. Ours is the first Covid-19 vaccine study to separately consider and directly compare the effects of monetary and goods-based incentives, both of which have been widely employed by countries seeking to increase uptake; we demonstrate that both types backfire equally. Results are compared against the burgeoning literature on Covid-19 vaccine incentives.

Counter-stereotypical messaging and partisan cues: Moving the needle on vaccines in a polarized United States

This paper reports results from a large-scale randomized controlled trial assessing whether counter-stereotypical messaging and partisan cues can induce people to get COVID-19 vaccines. The study used a 27-s video compilation of Donald Trump's comments about the vaccine from Fox News interviews and presented the video to millions of U.S. YouTube users through a $100,000 advertising campaign in October 2021. Results indicate that the number of vaccines increased in the average treated county by 103 (with a one-tailed P value of 0.097). Based on this average treatment effect and totaling across our 1014 treated counties, the total estimated effect was 104,036 vaccines.

College students' influence on COVID-19 vaccination uptake among seniors in China: a protocol of combined cross-sectional and experimental study

BACKGROUND

College students generally have good knowledge about COVID-19 and may facilitate COVID-19 vaccination in family. The purpose of this study is to understand college students' willingness to persuade their grandparents to initiate COVID-19 vaccination and the effect of their persuasion.

METHODS

A combined cross-sectional and experimental study will be conducted online. In the cross-sectional study (Phase I), eligible participants are college students who are aged ≥ 16 years and have at least one living grandparent aged ≥ 60 years who has/have not completed the COVID-19 vaccination. Participants self-complete Questionnaire A to collect information on the socio-demographics of themselves and their grandparents, their knowledge about older adults' COVID-19 vaccination, as well as Health Belief Model (HBM) and Theory of Planned Behavior (TPB) predictor variables. The primary outcome at Phase I is college students' willingness to persuade grandparents to receive COVID-19 vaccines. Those who are willing to persuade grandparents and participate in a follow-up survey will be invited to participate in a randomized controlled trial (Phase II). At Phase II, eligible participants are those who have at least one living grandparent aged ≥ 60 years who completed the COVID-19 initial vaccination series but has/have not received a booster dose. At the baseline, participants self-complete Questionnaire B to collect information on individual grandparents' COVID-19 vaccination status, attitude towards and intention to COVID-19 booster dose. Participants will then be randomly allocated 1:1 to either intervention arm (one-week smartphone-based health education on older adults' COVID-19 vaccination plus two weeks' waiting period) or control arm (three weeks' waiting period). At the end of week three, participants in both arms self-complete Questionnaire C to collect information on their grandparents' COVID-19 vaccination status. The primary outcome at Phase II is the uptake rate of COVID-19 booster dose among grandparents. Secondary outcomes include grandparents' attitude and intention to get a COVID-19 booster dose.

DISCUSSION

No previous study had measured the effect of college students' persuasion on COVID-19 vaccination uptake in older adults. Findings from this study will provide evidence for innovative and potentially feasible interventions that further promote COVID-19 vaccination in older adults.

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR2200063240. Registered 2 September 2022.

How Scientists View Vaccine Hesitancy

This paper examines possible causes, consequences, and potential solutions for addressing vaccine hesitancy in the United States, focusing on the perspectives of academic scientists. By examining the experiences of scientists, who are arguably a critical community in US society, we gain deeper insights into how they understand the complexities of vaccine hesitancy and whether their insights and opinions converge with or diverge from the current literature. We present findings from a national survey of a representative sample of academic scientists from the fields of biology and public health regarding vaccine hesitancy and related topics. Empirical analysis using descriptive, bivariate, and multivariate analyses covers multiple topics, including vaccine controversy, trust in science, causes of vaccine hesitancy, preferred policy and regulatory approaches, risk perceptions, and scientists' ethics and perceived communication roles. The results highlight a diversity of opinions within the scientific community regarding how to improve science-society communication in regard to vaccines, including the need to be transparent and candid to the public about the risk of vaccines and their research.

Between nudges and mandates: The drivers of COVID-19 vaccination intentions and subsequent uptake in Russia

Despite high levels of morbidity and mortality, as well as the widespread availability of domestic vaccines, Russia demonstrated significantly low rates of vaccination throughout the COVID-19 pandemic. This research explores vaccination intentions before the start of the immunisation campaign and the consequent uptake in Russia after the introduction of mandatory vaccination policy in certain industries and proof-of-immunisation for social activities. Using a nationally representative panel dataset, we analyse factors behind individual vaccination decisions using binary and multinomial logistic regressions. Special attention is given to the effect of employment in industries with vaccine mandates and personal factors which determine individual "nudgeability" to vaccination (e.g., personality traits, beliefs, vaccine alertness, self-perceived vaccine availability etc.). Our results show that 49 per cent of the population received at least one shot of COVID-19 vaccine by autumn 2021 after the introduction of mandatory vaccination. Vaccination intentions before the rollout of the nationwide immunisation campaign are correlated with the consequent attitudes and uptake, although the prediction is not perfect. 40 percent of vaccine refusers eventually got vaccinated, while 16 percent of vaccine supporters turned into refusers, revealing the lack of promotion of vaccine safety and effectiveness. To a large extent, vaccination refusal and hesitance are explained by vaccine alertness. Vaccine mandates significantly increased the uptake in several affected industries, especially education. These results offer important insights for designing information policy, relevant for future vaccination campaigns.

The politicized pandemic: Ideological polarization and the behavioral response to COVID-19

In a representative sample of the U.S. population during the first summer of the COVID-19 pandemic, we investigate how prosociality and ideology interact in their relationship with health-protecting behavior and trust in the government to handle the crisis. We find that an experimental measure of prosociality based on standard economic games positively relates to protective behavior. Conservatives are less compliant with COVID-19-related behavioral restrictions than liberals and evaluate the government's handling of the crisis significantly more positively. We show that prosociality does not mediate the impact of political ideology. This finding means that conservatives are less compliant with protective health guidelines - independent of differences in prosociality between both ideological camps. Behavioral differences between liberals and conservatives are roughly only one-fourth of the size of their differences in judging the government's crisis management. This result suggests that Americans were more polarized in their political views than in their acceptance of public health advice.

COVID-19 Vaccination Rate under Different Political Incentive: A Counterfactual Trend Approach Using Nationwide Data

(1) Background: France implemented a COVID-19 certificate in July 2021 to incentivize the population to uptake COVID-19 vaccines. However, little is known about the variation in its impact across age groups and its dependence on socio-demographic, economic, logistic, or political factors. (2) Methods: Using France's weekly first dose vaccination rate, a counterfactual trend approach allowed for the estimation of the vaccination rate across age groups at a small geographical level before and after the implementation of the health pass. The effect of the health pass was operationalized as the vaccination rate among those who would not be vaccinated without it. (3) Results: Vaccination before the health pass varied greatly among age groups and was mainly influenced by territory (lower in rural and overseas territories when compared to urban and metropolitan ones), political beliefs, and socio-economic disparities. Vaccine logistics played a minor but significant role, while the impact of COVID-19 did not affect the vaccination rate. The health pass increased the vaccination overall but with varying efficiency across groups. It convinced mainly young people politically close to the governmental vaccination strategy and living in urban metropolitan areas with low socio-economical discrepancies. The selected variables explained most of the variability of the vaccination rate before the health pass; they explained, at most, a third of the variation in the health pass effect on vaccination. (4) Conclusions: From a public health perspective, the French health pass increased the overall vaccination, but failed to promote preventive behaviours in all segments of society, particularly in vulnerable communities.

Providing freedom or financial remuneration? A cross-sectional study on the role of monetary and legal incentives on COVID-19 further booster vaccination intention in the Italian context

Vaccine hesitancy became a more and more important issue during the COVID-19 pandemic. Due to the emergence of new variants, many international health agencies have already begun administering booster doses of the vaccine in response to these threats. Studies have emphasized the effectiveness of different types of incentive-based strategies to increase vaccination behaviors. The purpose of the present study was to identify the correlation between different types of incentives (legal or financial) with people's intentions to get a COVID-19 booster vaccine. We conducted a cross-sectional study between 29 January 2022 and 03 February 2022. An online quantitative survey was carried out in Italy. One thousand and twenty-two Italian adults were recruited by a professional panel provider. Descriptive statistics were computed for the five variables concerning the incentives (monetary, tax, fee, health certification, travel) toward vaccination. A general linear model (GLM) was then computed to compare the scores of the five different variables within the subjects. The general linear model showed a significant within-subjects main effect. Post-hoc comparisons showed that among the financial incentive, the monetary reward is rated lower than all the others. Tax and fees both resulted lower than both the legal incentives. Finally, COVID-19 health certification and travel did not result significantly different from each other. This study offers an important contribution to public policy literature and to policymakers in their efforts to explain and steer booster vaccination acceptance while facing an ongoing pandemic.

How to reduce vaccination hesitancy? The relevance of evidence and its communicator

Even though the immediate urgency of the COVID-19 pandemic seems to have passed, many countries did not reach the vaccination rates they initially aimed for. The stagnation in vaccine uptake during the height of the pandemic presented policy makers with a challenge that remains unresolved and is paramount for future pandemics and other crises: How to convince the (often not insubstantial) unvaccinated proportion of the population of the benefits of a vaccination? Designing more successful communication strategies, both in retrospect and looking ahead, requires a differentiated understanding of the concerns of those that remain unvaccinated. Guided by the elaboration likelihood model, this paper has two objectives: First, it explores by means of a latent class analysis how unvaccinated individuals might be characterized by their attitudes towards COVID-19 vaccination. Second, we investigate to what extent (i) varying types of evidence (none/anecdotal/statistical) can be employed by (ii) different types of communicators (scientists/politicians) to improve vaccination intentions across these subgroups. To address these questions, we conducted an original online survey experiment among 2145 unvaccinated respondents from Germany where a substantial population share remains unvaccinated. The results suggest three different subgroups, which differ regarding their openness towards a COVID-19 vaccination: Vaccination opponents (N = 1184), sceptics (N = 572) and those in principle receptive (N = 389) to be vaccinated. On average, neither the provision of statistical nor anecdotal evidence increased the persuasiveness of information regarding the efficacy of a COVID-19 vaccine. However, scientists were, on average, more persuasive than politicians (relatively increase vaccination intentions by 0.184 standard deviations). With respect to heterogeneous treatment effects among the three subgroups, vaccination opponents seem largely unreachable, while sceptics value information by scientists, particularly if supported by anecdotal evidence (relatively increases intentions by 0.45 standard deviations). Receptives seem much more responsive to statistical evidence from politicians (relatively increases intentions by 0.38 standard deviations).

How does the vaccine approval procedure affect COVID-19 vaccination intentions?

People's willingness to vaccinate is critical to combating the COVID-19 pandemic. We devise a representative experiment to study how the design of the vaccine approval procedure affects trust in newly developed vaccines and consequently public attitudes towards vaccination. Compared to an Emergency Use Authorization, choosing the more thorough Conditional Marketing Authorization approval procedure increases vaccination intentions by 13 percentage points. The effects of the increased duration of the approval procedure are positive and significant only for Emergency Use Authorization. Treatment effects do not differ between relevant subgroups, such as respondents who had (did not have) COVID-19, or between vaccinated and unvaccinated respondents. Increased trust in the vaccine is the key mediator of treatment effects on vaccination intentions.

Fear of COVID-19 disease and vaccination as predictors of vaccination status

Vaccination rates are still insufficient to prevent the spread of COVID-19, so immunity must be increased among the population in order to reduce the virus' spread and the associated medical and psychosocial effects. Although previous work has identified various factors associated with a low willingness to get vaccinated, the role of emotions such as fear of vaccination (FVAC) or fear of COVID-19 (FCOV), vaccination as a subjective norm (SN), psychological factors like general control beliefs (CB) or psychological resilience, and their interaction have been investigated less intensively. We used data from three cross-sectional waves of the German Panel COSMO (November 2021, N = 1010; February 2022, N = 1026; March 2022, N = 1031) and multiple logistic regression analyses to test whether vaccination rates are moderated by those factors. After controlling for covariates (age, sex, confidence in own intuition, optimism, well-being), we found that CB was no significant predictor of vaccination status. Higher FCOV and higher ratings in SN, however, were associated with an increased likelihood of being vaccinated. In contrast, higher FVAC was associated with a decreased likelihood of being vaccinated. Psychological resilience did not consistently moderate the associations between fear and vaccination status.

COVID-19 knowledge deconstruction and retrieval: an intelligent bibliometric solution

COVID-19 has been an unprecedented challenge that disruptively reshaped societies and brought a massive amount of novel knowledge to the scientific community. However, as this knowledge flood continues surging, researchers have been disadvantaged by not having access to a platform that can quickly synthesize emerging information and link the new knowledge to the latent knowledge foundation. Aiming to fill this gap, we propose a research framework and develop a dashboard that can assist scientists in identifying, retrieving, and understanding COVID-19 knowledge from the ocean of scholarly articles. Incorporating principal component decomposition (PCD), a knowledge mode-based search approach, and hierarchical topic tree (HTT) analysis, the proposed framework profiles the COVID-19 research landscape, retrieves topic-specific latent knowledge foundation, and visualizes knowledge structures. The regularly updated dashboard presents our research results. Addressing 127,971 COVID-19 research papers from PubMed, the PCD topic analysis identifies 35 research hotspots, along with their inner correlations and fluctuating trends. The HTT result segments the global knowledge landscape of COVID-19 into clinical and public health branches and reveals the deeper exploration of those studies. To supplement this analysis, we additionally built a knowledge model from research papers on the topic of vaccination and fetched 92,286 pre-Covid publications as the latent knowledge foundation for reference. The HTT analysis results on the retrieved papers show multiple relevant biomedical disciplines and four future research topics: monoclonal antibody treatments, vaccinations in diabetic patients, vaccine immunity effectiveness and durability, and vaccination-related allergic sensitization.

Attitudes towards COVID-19 vaccination among incarcerated persons in the Federal Bureau of Prisons, June-July 2021

OBJECTIVE

To understand the attitudes towards COVID-19 vaccination and trusted sources of vaccination-related information among persons incarcerated in the Federal Bureau of Prisons.

METHODS

From June-July 2021, persons incarcerated across 122 facilities operated by the Federal Bureau of Prisons were invited to participate in a survey asking their reasons for receiving or declining COVID-19 vaccination and the information sources they relied upon to make these decisions. Descriptive analyses were conducted.

RESULTS

A total of 130,789 incarcerated persons with known vaccination status were invited to participate in the survey. At the time of survey, 78,496 (62%) were fully vaccinated; 3,128 (3%) were partially vaccinated and scheduled to complete their second dose, and 44,394 (35%) had declined either a first or second dose. 7,474 (9.5%) of the fully vaccinated group and 2,302 (4.4%) of the group declining either a first or second dose chose to participate in the survey; an overall survey return rate of 7.6% (n = 9,905). Among vaccinated respondents, the most common reason given for accepting vaccination was to protect their health (n = 5,689; 76.1%). Individuals who declined vaccination cited concerns about vaccine side effects (n = 1,304; 56.6%), mistrust of the vaccine (n = 1,256; 54.6%), and vaccine safety concerns (n = 1,252; 54.4%). Among those who declined, 21.2% (n = 489) reported that they would choose to be vaccinated if the vaccine was offered again. Those who declined also reported that additional information from outside organizations (n = 1128; 49.0%), receiving information regarding vaccine safety (n = 841; 36.5%), and/or speaking with a trusted medical advisor (n = 565; 24.5%) may influence their decision to be vaccinated in the future.

CONCLUSION

As the COVID-19 pandemic continues, it is important to increase vaccine confidence in prisons, jails, and detention facilities to reduce transmission and severe health outcomes. These survey findings can inform the design of potential interventions to increase COVID-19 vaccine uptake in these settings.

Vaccine-hesitant people misperceive the social norm of vaccination

Vaccine hesitancy is one of the main threats to global health, as became clear once more during the COVID-19 pandemic. Vaccination campaigns could benefit from appeals to social norms to promote vaccination, but without awareness of the social norm in place any intervention relying on social norms may backfire. We present a two-step approach of social norm diagnosis and intervention that identifies both whether a vaccination norm exists or develops over time and corrects misperceptions. In two studies (N = 887 and N = 412 ) conducted in Rome, Italy from June to August 2021 (during the first COVID-19 vaccination campaign), we show that vaccine-hesitant people strongly underestimated vaccine acceptance rates for COVID-19 despite increases in region-wide vaccination rates. This suggests a false consensus bias on the social norm of vaccination. We presented a subgroup of vaccine-hesitant people with the accurate vaccine acceptance rates (both planned uptake and vaccine approval) and tested if this social information would lower their vaccine hesitancy. We do not find clear effects, most likely because of the introduction of the COVID-19 health certificate (the "green pass") that was implemented during our data collection. The green pass reduced both misperceptions in the social norm and vaccine hesitancy, thus undermining our treatment effect. We conclude that to alleviate misperceptions on the social norm of vaccination in early stages of the vaccination campaign governments and media should report not just the current vaccination rate, but also about vaccination intentions and approval.

Why school is crucial to increase vaccination coverage for children: Evaluation of school vaccination check program in South Korea 2021-2022

The School Vaccination Check Program (SVCP) is a public health measure that aims to achieve high levels of National Immunization Program (NIP) vaccination coverage for children by checking the completion of the vaccination schedule for students when they enter elementary or middle school. Due to the COVID-19 pandemic, the SVCP was stopped in 2020 and 2021, and restarted in June-August 2022. In this study, we examined and quantified the relationship with SVCP and the vaccination uptake by comparing the vaccination coverage of 2021 and 2022. Based on the standard schedule, the vaccination records of DTaP5, IPV4, MMR2 and IJEV4 were evaluated for elementary school students. The Tdap6, IJEV5 and HPV1 were evaluated for the students from middle school. Using a difference-in-difference study design and national level big data, the study compared vaccination coverage as of August 2021 and 2022. The study found that the SVCP was effective in increasing vaccination coverage for targeted vaccinations such as DTaP5, IPV4, MMR2 and IJEV4 for elementary school students, and Tdap6, IJEV5 for middle school students. However, the SVCP did not show a statistically significant effect on increasing vaccination coverage on HPV1 for middle school students. School can play an important role to improve vaccination coverage. Therefore, close collaboration with health and education authority is crucial to accomplish successful vaccination program reducing vaccine preventable disease outbreaks in schools.