Abstract
Objective
This study seeks to comparatively examine parents’ intention to vaccinate their children for three infectious diseases, including COVID-19, HPV, and monkeypox.
Methods
Utilizing a mixed-design survey and multilevel structural equation models, we investigated if perception of the diseases and vaccines explained the variance in parents’ vaccine-specific decision-making and population difference in vaccination intention.
Results
Compared with the COVID-19 vaccine, parents were more willing to get an HPV vaccine for their children due to greater perceived benefit and lower perceived barrier. Concerns about vaccine safety and lower disease risk perception were associated with lower intention to get a monkeypox vaccine. Parents of color, less educated, and lower-income parents were less willing to get vaccines for their children due to low benefit perception and high perceived barriers.
Conclusion
Parents were motivated by different social and psychological factors when deciding whether to get a COVID-19, HPV, and monkeypox vaccine for their children.
Practice implications
Vaccine promotion should be tailored to the characteristics of the target population and the vaccines. Underprivileged communities may be better approached with information about vaccine benefit and barriers, and vaccines for unfamiliar diseases may be better communicated with disease risk information.
Keywords: COVID-19, HPV, Monkeypox, Vaccine, HBM
1. Introduction
The recent COVID-19 pandemic again highlighted the threats of infectious diseases. Since the inception of human history, infectious diseases such as smallpox and plague have caused countless deaths and economic losses. Fortunately, the wide adoption of vaccines and public health measures such as improved living environment bring hope to the millennial struggle [1]. However, despite its success in reducing the threats of vaccine-preventable diseases (VPD), there is a rise in skepticism against vaccines [2]. Vaccine hesitancy, defined as the delay and refusal of a vaccine despite its availability [3], has led to the resurgence of VPDs. Exacerbating the situation, parents skeptical of childhood vaccines are more reluctant to get a vaccine for children [4], posing threats to their health [5]. Investigating parental vaccine hesitancy is critical. First, many vaccines are administered during childhood to maximize protective effects. As parents often make children’s medical decisions [6], their attitudes and behaviors are essential to understanding vaccine hesitancy and mitigation strategies. Additionally, as children are often viewed as a more vulnerable population, parents may scrutinize children’s vaccines more stringently than adult vaccines [7], [8], which lead to different vaccine decision-making.
Growing attention has been devoted to investigating the determinants and influence of parental vaccine hesitancy [9]. However, research often focuses on one vaccine at a time [4], while disregarding the differences in perceptions and behaviors associated with other vaccines. To untangle the complex interplay of factors that shape parents’ intention to vaccinate children, we concurrently assess different social and psychological factors’ influences on parents’ intention to get three types of vaccines for children, including the COVID-19 vaccine, human papillomavirus (HPV) vaccine, and monkeypox vaccine. Although these vaccines differ in availability and novelty, their similarities allow a meaningful and fair comparison. First, neither of COVID-19 and monkeypox vaccines are mandated in the U.S. and only a few states such as Rhode Island require HPV vaccination, making it a voluntary decision for most parents. Moreover, the threats posed by COVID-19, HPV, and monkeypox are associated with higher level of uncertainty. Specifically, the mortality and morbidity rates of COVID-19 are lower among children, and HPV-related diseases often take years to develop. Similarly, monkeypox, as a novel disease in the U.S., may also be associated with high uncertainty.
The vaccines developed for the VPDs also bear differences. COVID-19 vaccines for children were approved much later due to more stringent testing [10]. COVID-19 vaccination rates for children are also lower than those for the older population [11]. Considering the decline in people’s intention to receive a booster vaccine for COVID-19 [12], it is likely that the proportion of parents opting to get booster COVID-19 vaccines for children may be even lower. Differently, the HPV vaccine tends to be more familiar to parents. Extensive research examined parents’ intention to get an HPV vaccine for their children [8], [13], [14], but few compared it with perceptions and behaviors associated with other vaccines. Unlike the COVID-19 and HPV vaccines, there is no approved monkeypox vaccine for children at the time of this study. However, as monkeypox has been declared a public health emergency in the U.S. and child infections have been reported [15], parents may perceive the disease and its vaccine as a salient health concern. Coupled with the recent memory of mass vaccination against COVID-19, parents may be motivated to contemplate the possibility of getting such a vaccine for their children when it becomes available. Together, the similarities and variance among COVID-19, HPV, and monkeypox and their vaccines make them ideal candidates for a comparative analysis of the factors that predict parents’ vaccination intention.
We refer to the health belief model (HBM) to systematically examine social and psychological factors’ influences on parental vaccination intention. HBM has long been adopted to predict and explain the initiation of various health behaviors, such as vaccination, screening, and lifestyle change [16], [17]. The model specifies three sets of sociopsychological factors associated with behaviors, including appraisals of the threat, the health behavior, and self-efficacy [16]. Threat appraisal, also termed risk perception, is often operationalized as the perceived severity of and susceptibility to a health threat [18]. The former characterizes the magnitude of the health threat, while the latter demarcates likelihood of the threat. For example, people who believe that COVID-19 may lead to severe consequences and are vulnerable to such threats are more likely to take action such as vaccination[17]. In terms of the three diseases, the difference in their salience may also lead to different levels of threat appraisal, above and beyond their actual health consequences.
In addition, people’s evaluative beliefs associated with health behavior purported to address the health threat also influence adaptive behavior [16], [18]. HBM specifies that such perceptions can often be categorized into two sub-groups of variables, including perceived benefits and barriers [16]. In the vaccination context, perceived benefits are often operationalized as a vaccine’s effectiveness in preventing or reducing the harm of its target diseases [18]. Perceived barriers, on the other hand, often involve concerns about vaccine safety, cost, and availability [19]. As illustrated earlier, parents in the U.S. likely have different perceptions of the three vaccines due to the difference in their familiarity, availability, and media coverage. Though millions of doses of COVID-19 vaccines have been administered worldwide and it is freely available in many areas in the U.S., widespread misinformation damages its reputation as a safe and effective vaccine [20], [21]. HPV vaccines, despite being subject to some political controversy earlier on, received less controversial and politicized news coverage at the time of this study. However, it is not provided for free for many in the U.S., causing barriers to vaccine access [22], [23]. Furthermore, as a monkeypox vaccine for children is yet available in the U.S., parents may be more concerned about its safety and effectiveness due to the lack of information. Therefore, it is likely that parents may have different views on these vaccines, which according to HBM, may lead to different vaccination intentions.
The last set of variables specified in HBM pertains to self-efficacy [24]. In the HBM context, self-efficacy characterizes a person’s belief in performing a health behavior, such as receiving COVID-19 and HPV vaccines [17], [25]. In addition to perceived self-efficacy, recent research also begins to recognize the effects of emotional self-efficacy [26], [27]. Unlike the classic construct, emotional self-efficacy focuses on a person’s belief about their ability to understand, control, and utilize emotions to regulate health behaviors [28]. For example, studies show that parents with higher emotional self-efficacy were more likely to get a vaccine for their children, as they can detect and moderate the anxiety, fear, and distress and use positive emotions to relax the tense situation [29]. Considering the unique role played by emotional self-efficacy, we expand the traditional HBM to incorporate it to assess different factors’ influence on vaccination intention. Notably, unlike classic self-efficacy, which is often operationalized as a behavior-specific construct, emotional self-efficacy tends to be a personal-level trait that serves to regulate different behaviors. For example, a parent may believe that they are emotionally capable of taking their children to multiple vaccine appointments, but they feel more efficacious in getting a COVID-19 vaccine than HPV vaccine. Such a distinction is important in the current research as we utilize a multi-level model to concurrently assess vaccine-specific and individual-level factors’ influence. Emotional self-efficacy is thus operationalized at the person-level.
Correspondingly, we propose a set of hypotheses and research questions. As our goal is to compare factors’ influence on vaccination intention, a within-subject survey was conducted to assess parents’ perceptions of COVID-19, HPV, and monkeypox and vaccines. In addition to the HBM variables, we also measured individual characteristics, such as age, race, and vaccination history, which were shown to strongly influence vaccine hesitancy [3], [30]. Furthermore, as mothers are often the ones in charge of children’s vaccination decisions [8], [31], we selectively sampled individuals who identified as a woman and have at least one child. Lastly, due to the comparative nature of the current inquiry, we are interested in not only the direct effects of the focal variables on intention, but also the indirect effects of vaccine type and individual characteristics mediated by the HBM variables. Specifically, we seek to identify if parents from different backgrounds hold different views of different diseases and their vaccines, and if such difference explain their varied intention to get a vaccine for their children.
H1: Emotional self-efficacy is positively associated with parents’ intention to get COVID-19, HPV, and Monkeypox vaccines for their children.
RQ1: Do parents perceive COVID-19, HPV, and Monkeypox and their vaccines differently in terms of the perceived threat of the diseases (RQ1a), perceived benefits and barriers of vaccination (RQ1b), perceived self-efficacy in getting these vaccines (RQ1c)?
RQ2: Do perceived threats, benefits and barriers, and self-efficacy explain the difference in parents’ intention to vaccinate their children for COVID-19, HPV, and Monkeypox?
RQ3: Do perceived threat, benefits and barriers, and self-efficacy explain the effects of individual characteristics on parents’ intention to vaccinate their children for COVID-19, HPV, and Monkeypox?
2. Methods
A survey was delivered to a sample recruited from panels maintained by Prolific.co in July 2022. We screened for female U.S. participants with at least one child, who were rewarded $1.80 for participating in the study. An a priori power analysis using semPower package in R (RMSEA = 0.02, alpha = 0.05, beta = 0.05, df = 500) shows that 574 observations are needed for the measurement model. After providing informed consent, 1029 participants responded to the questionnaire. Among them, 954 completed the questionnaire and passed two attention checks.
Participants were asked to indicate their perceptions and behavioral intentions associated with two of the three diseases/vaccines to avoid fatigue. The order of the questions was also counterbalanced. A unique I.D. was assigned to each participant and used as the clustering variable. We screened the dataset according to several criteria. First, as there is no available monkeypox vaccine for children in the U.S., responses were removed if the participant indicated that their children had received a dose of the vaccine. We also removed vaccine-level entries associated with HPV vaccine from those who have vaccinated their children for HPV. Differently, as additional COVID-19 booster vaccines are expected to be available, we retained participants indicating that their children had received COVID-19 vaccines but measured vaccination intention differently (i.e., intention to receive additional COVID-19 vaccine booster). As a result, 1624 responses from 812 participants whose children were 18 years old or younger were retained. Table 1 shows the sample demographics.
Table 1.
Sample demsographics.
| Variables | Sample percentage or M (S.D.) |
|---|---|
| Age of the mother | 33.34 (4.35) |
| Age of their youngest child | 4.70 (3.76) |
| Race | |
| Non-Hispanic White | 78.2 % |
| Non-Hispanic Black | 10.3 % |
| Hispanic | 6.8 % |
| Asian/Pacific Islanders/Native American | 3.2 % |
| Others | 1.5 % |
| Education | |
| Less than high school | 0.4 % |
| High school | 10.1 % |
| Some college | 22.9 % |
| 2-year college degree | 13.7 % |
| 4-year college degree | 36.2 % |
| Master’s degree | 13.1 % |
| Doctoral or professional degree | 3.7 % |
| Income | |
| Less than $15,000 | 4.3 % |
| $15,000 - $24,999 | 6.7 % |
| $25,000 - $34,999 | 11.0 % |
| $35,000 - $49,999 | 10.7 % |
| $50,000 - $74,999 | 21.8 % |
| $75,000 - $99,999 | 18.7 % |
| $100,000 - $149,999 | 15.9 % |
| $150,000 or more | 11.0 % |
| Children vaccination status (at least received some children vaccines recommended by CDC) | 90.5 % |
The key measures were all adopted from existing research [17], [18], [32]. Measurement items, reliability indices, means, and standard deviations of the scales are presented in Table 2.
Table 2.
Descriptive statistics and composite reliability of survey measures.
| M | SD | Reliability | |
|---|---|---|---|
| Participant’s intention to vaccinate their children | |||
| COVID-19 vaccine | 3.39 | 1.60 | α = 0.98 |
| Consider getting a COVID-19 vaccine for your children. (1 “very unlikely” to 5 “very likely”). | 3.51 | 1.62 | |
| Try to get a COVID-19 vaccine for your children. | 3.29 | 1.65 | |
| Actually get your children a COVID-19 vaccine. | 3.27 | 1.63 | |
| HPV vaccine | 3.74 | 1.39 | α = 0.98 |
| Consider getting an HPV vaccine for your children. | 3.90 | 1.34 | |
| Try to get an HPV vaccine for your children. | 3.71 | 1.41 | |
| Actually get your children an HPV vaccine. | 3.72 | 1.40 | |
| Monkeypox vaccine | 2.48 | 1.33 | α = 0.97 |
| Consider getting a monkeypox vaccine for your children when it is available. | 2.76 | 1.48 | |
| Try to get a monkeypox vaccine for your children when it is available. | 2.48 | 1.37 | |
| Actually get your children a monkeypox vaccine when it is available. | 2.41 | 1.33 | |
| Perceived susceptibility | |||
| COVID-19 | 3.82 | 0.93 | α = 0.85 |
| It is likely that my children will get COVID-19. (1 “strongly disagree” to 5 “strongly disagree”) | 3.54 | 1.11 | |
| My children are at the risk of getting COVID-19. | 3.72 | 1.10 | |
| It is possible that my children will get the COVID-19. | 4.04 | 0.95 | |
| HPV | 3.01 | 0.90 | α = 0.80 |
| It is likely that my children will contract HPV. | 2.62 | 1.00 | |
| My children are at the risk of contracting HPV. | 2.97 | 1.13 | |
| It is possible that my children will contract HPV. | 3.41 | 1.07 | |
| Monkeypox | 2.54 | 0.89 | α = 0.84 |
| It is likely that my children will get monkeypox. | 2.23 | 0.92 | |
| My children are at the risk of getting monkeypox. | 2.60 | 1.04 | |
| It is possible that my children will get monkeypox. | 2.93 | 1.12 | |
| Perceived susceptibility | |||
| COVID-19 | 3.76 | 1.05 | α = 0.91 |
| I believe that COVID-19 is a severe health problem. (1 “strongly disagree” to 5 “strongly disagree”) | 3.77 | 1.15 | |
| I believe that COVID-19 has serious negative consequences. | 3.82 | 1.11 | |
| I believe that COVID-19 is extremely harmful. | 3.68 | 1.15 | |
| HPV | 3.82 | 0.88 | α = 0.85 |
| I believe that HPV infection is a severe health problem. | 3.79 | 0.98 | |
| I believe that HPV infection has serious negative consequences. | 3.87 | 1.01 | |
| I believe that HPV infection is extremely harmful. | 3.78 | 1.03 | |
| Monkeypox | 3.34 | 0.95 | α = 0.90 |
| I believe that Monkeypox is a severe health problem. | 3.28 | 1.07 | |
| I believe that Monkeypox has serious negative consequences. | 3.44 | 1.04 | |
| I believe that Monkeypox is extremely harmful. | 3.36 | 0.99 | |
| Perceived benefits of the vaccine | |||
| COVID-19 vaccine | 3.16 | 1.31 | α = 0.96 |
| The COVID-19 vaccine will work in preventing the disease. (1 “strongly disagree” to 5 “strongly disagree”) | 3.14 | 1.34 | |
| The COVID-19 vaccine will be effective in preventing the disease. | 3.14 | 1.35 | |
| If my children get the vaccines, they will be less likely to get COVID-19. | 3.20 | 1.40 | |
| HPV vaccine | 3.96 | 0.92 | α = 0.93 |
| The HPV vaccine will work in preventing the disease. | 3.97 | 0.95 | |
| The HPV vaccine will be effective in preventing the disease. | 3.98 | 0.94 | |
| If my children get the vaccines, they will be less likely to contract HPV. | 4.03 | 0.97 | |
| Monkeypox vaccine | 3.30 | 0.92 | α = 0.92 |
| The monkeypox vaccine will work in preventing the disease. | 3.28 | 0.99 | |
| The monkeypox vaccine will be effective in preventing the disease. | 3.30 | 0.97 | |
| If my children get the vaccines, they will be less likely to get monkeypox. | 3.42 | 1.05 | |
| Perceived barriers of the vaccine: Safety concern | |||
| COVID-19 vaccine | 2.88 | 1.53 | α = 0.94 |
| I have concerns about whether the COVID-19 vaccine is safe for children. (1 “not at all” to 5 “a great deal”) | 2.95 | 1.64 | |
| I concerned that there is not enough research done on the COVID-19 vaccines. | 2.73 | 1.60 | |
| I have concerns about possible side effects of the COVID-19 vaccine. | 2.97 | 1.62 | |
| HPV vaccine | 2.23 | 1.31 | α = 0.92 |
| I have concerns about whether the HPV vaccine is safe for children. | 2.24 | 1.44 | |
| I concerned that there is not enough research done on the HPV vaccines. | 1.84 | 1.24 | |
| I have concerns about possible side effects of the HPV vaccine. | 2.27 | 1.40 | |
| Monkeypox vaccine | 3.21 | 1.35 | α = 0.89 |
| I have concerns about whether the monkeypox vaccine is safe for children. | 3.31 | 1.45 | |
| I concerned that there is not enough research done on the monkeypox vaccines. | 3.11 | 1.50 | |
| I have concerns about possible side effects of the monkeypox vaccine. | 3.10 | 1.49 | |
| Perceived barriers of the vaccine: Cost concern | |||
| COVID-19 vaccine | 1.22 | 0.54 | α = 0.73 |
| I am not sure how to file the insurance claim to get reimbursed for the COVID-19 vaccine. (1 “not at all” to 5 “a great deal”) | 1.35 | 0.84 | |
| The cost of COVID-19 vaccine is too expensive. | 1.23 | 0.67 | |
| My insurance may not cover the COVID-19 vaccine. | 1.22 | 0.69 | |
| HPV vaccine | 1.43 | 0.78 | α = 0.81 |
| I am not sure how to file the insurance claim to get reimbursed for the HPV vaccine. | 1.44 | 0.95 | |
| The cost of HPV vaccine is too expensive. | 1.42 | 0.88 | |
| My insurance may not cover the HPV vaccine. | 1.44 | 0.93 | |
| Monkeypox vaccine | 2.01 | 1.10 | α = 0.83 |
| I am not sure how to file the insurance claim to get reimbursed for the monkeypox vaccine. | 2.07 | 1.38 | |
| The cost of monkeypox vaccine is too expensive. | 1.95 | 1.21 | |
| My insurance may not cover the monkeypox vaccine. | 1.97 | 1.24 | |
| Perceived self-efficacy | |||
| COVID-19 vaccine | 4.35 | 0.74 | α = 0.87 |
| I am able to get the COVID-19 vaccine for my children. (1 “strongly disagree” to 5 “strongly disagree”) | 4.31 | 0.87 | |
| It is easy to get the COVID-19 vaccine for my children. | 4.24 | 0.91 | |
| I know how to get the COVID-19 vaccine for my children. | 4.40 | 0.78 | |
| HPV vaccine | 4.18 | 0.83 | α = 0.90 |
| I am able to get the COVID-19 vaccine for my children. | 4.21 | 0.87 | |
| It is easy to get the COVID-19 vaccine for my children. | 4.18 | 0.88 | |
| I know how to get the COVID-19 vaccine for my children. | 4.21 | 0.92 | |
| Monkeypox vaccine | 2.43 | 0.90 | α = 0.85 |
| I am able to get the COVID-19 vaccine for my children. | 2.78 | 1.02 | |
| It is easy to get the COVID-19 vaccine for my children. | 2.55 | 1.02 | |
| I know how to get the COVID-19 vaccine for my children. | 2.22 | 1.18 | |
| Emotional self-efficacy | 4.16 | 0.56 | α = 0.86 |
| I am able to understand what may cause my children’s emotion to change when getting them a vaccine. (1 “strongly disagree” to 5 “strongly disagree”) | 3.89 | 0.89 | |
| I can figure out what may cause my emotion to change when getting my children vaccinated. | 3.95 | 0.83 | |
| I can correctly identity my own emotion when getting my children vaccinated. | 4.21 | 0.70 | |
| I notice the emotion my children’s body language portrays when getting them a vaccine. | 4.12 | 0.78 | |
| I use positive emotions to generate good health decisions for my children. | 4.34 | 0.69 | |
| I can regulate my emotion when getting my children vaccinated. | 4.27 | 0.76 | |
| I am able to help my children calm down when they are feeling anxious or afraid of receiving a vaccine. | 4.21 | 0.78 |
Multilevel structural equation models (MSEM) were utilized to address the research questions. Following the two-step approach delineated in Kline [33], we first conducted a multilevel confirmatory analysis (MCFA) to assess the measurement model. After adjusting the covariance between some measurement items to allow for common method-related variance, the model achieved a satisfactory fit (χ² = 1321.440, DF= 499, RMSEA = 0.032, CFI = 0.977, TLI = 0.972, SRMR-within = 0.055, SRMR-between = 0.175). Following the conventional approach in MSEM, fewer factors were modeled at the person (i.e., between) than the vaccine (i.e., within) level [34]. Specifically, threat appraisal variables and perceived barriers (i.e., safety and cost concerns) were modeled as single factors at the person-level. Other factors were modeled similarly across levels. Building on the MCFA model, we analyzed the structural model according to the research questions and hypothesis. Vaccine type was dummy-coded into two variables, each representing the comparison between HPV and COVID-19 and monkeypox and COVID-19. Individual characteristics such as age, racial and ethnic background, education, family income, and child vaccination history were modeled as person-level predictors of vaccination intention. The structural model fit the data adequately (χ² = 2177.669, DF= 740, RMSEA = 0.035, CFI = 0.962, TLI = 0.954, SRMR-within = 0.088, SRMR-between = 0.162). Notably, as the bias-corrected confidence interval is not available for MSEM, we estimated the 95 % credibility interval of indirect effects using a Bayesian estimator for the model as a supplement to the significance test. Unlike the 95 % confidence interval estimated based on the bootstrapped z-scores, the 95 % credibility interval is estimated according to the posterior distribution of the effects [34].
3. Results
Direct effects of the vaccine type, HBM variables, and individual characteristics are presented in Table 3 and Table 4. Observably, perceived benefit of the vaccine was positively correlated with vaccination intention at both levels. Safety concerns and perceived barriers were negatively associated with vaccination at both levels. Risk perception and its sub-factors were also positively associated with vaccination intention. However, self-efficacy or emotional self-efficacy was not significantly related to vaccination intention. H1 was thus rejected.
Table 3.
Unstandardized coefficient estimates for the vaccine-level (within level) paths.
| Vaccination Intention | Perceived Benefit | Self-Efficacy | Safety Concern | Cost Concern | Perceived Susceptibility | Perceived Severity | |
|---|---|---|---|---|---|---|---|
| Perceived Benefit | 0.18*** | ||||||
| Self-Efficacy | 0.07 | ||||||
| Safety Concern | -0.39*** | ||||||
| Cost Concern | 0.04 | ||||||
| Perceived Susceptibility | 0.37*** | ||||||
| Perceived Severity | 0.26*** | ||||||
| HPV1 | 0.20** | 0.79*** | -0.17*** | -0.66*** | 0.22*** | -0.87*** | 0.03 |
| Monkeypox1 | -0.02 | 0.11* | -1.65*** | 0.4*** | 0.86*** | -1.36*** | -0.43*** |
Note. 1 Dummy-coded vaccine/disease type variable with COVID-19 as the reference group; * p < .05; ** p < .01; *** p < .001
Table 4.
Unstandardized coefficient estimates for the person-level (between level) paths.
| Vaccination Intention | Perceived Benefit | Perceived Barrier | Perceived Risks | Self-Efficacy | Emotional Self-Efficacy | |
|---|---|---|---|---|---|---|
| Perceived Benefit | 0.7*** | |||||
| Perceived Barrier | -0.33*** | |||||
| Perceived Risks | 0.54** | |||||
| Self-Efficacy | 0.08 | |||||
| Emotional Self-Efficacy |
0.03 | |||||
| Age | 0.000 | -0.01 | 0.01 | -0.01 | 0.002 | 0.002 |
| Black or African American1 | 0.07 | -0.39*** | 0.71*** | -0.15* | -0.12 | -0.03 |
| Hispanic or Latina2 | 0.02 | -0.06 | 0.14 | -0.06 | 0.02 | -0.02 |
| Asian, Pacific Islander, or Native American3 | -0.19 | -0.18 | 0.64** | 0.01 | -0.14 | -0.03 |
| Other race or ethnicity4 | 0.02 | -0.21 | 0.02 | -0.18 | -0.17 | -0.17 |
| Education | 0.01 | 0.08** | -0.09* | 0.03* | -0.02 | -0.003 |
| Income | -0.04* | 0.03 | -0.09** | -0.02 | 0.05*** | 0.02 |
| Youngest child’s age | -0.02 | -0.002 | -0.01 | -0.004 | 0.01* | 0.003 |
| Youngest Child’s vaccination experience2 | 0.14 | 0.6*** | -0.84*** | 0.31*** | 0.29*** | 0.23** |
Note. 1 Dummy-coded race/ethnicity variable with non-Hispanic White as the reference group; 2 Dummy-coded vaccination experience variable (1 = received all or part of CDC-recommended vaccines for children; 0 = did not receive any CDC-recommended vaccines for children); * p < .05; ** p < .01; *** p < .001
In response to RQ1, we also examined the direct effects of vaccine type on parents’ perception of the vaccines, diseases, and intention. Observably, our participants were more likely to get an HPV vaccine for children than a COVID-19 vaccine when the effects of other perceptual variables were controlled, but the difference between monkeypox and COVID-19 vaccination intention was not significant. Participants also perceived the HPV and monkeypox vaccines as more beneficial than the COVID-19 vaccines. However, their perceived self-efficacy in getting the HPV and monkeypox vaccines were lower than that of the COVID-19 vaccines. Safety was less of a concern regarding the HPV vaccine, but it was a more salient concern for monkeypox vaccines compared to the COVID-19 vaccines. Cost concerns were also a more influential barrier for both the HPV and monkeypox vaccines than for the COVID-19 vaccines. Participants perceived their children as less susceptible to HPV and monkeypox than COVID-19 but only perceived monkeypox as a less severe threat than COVID-19. We also examined the influence of individual characteristics on perceptual variables. Observably, compared with White parents, Black participants were more likely to have lower perceived benefits of the vaccine, higher perceived behavioral barriers, and lower risk perception. Asian participants also indicated higher perceived barriers. Prior vaccination history was conducive to all the HBM variables. Education and income were also related to benefit, self-efficacy, and barrier perceptions.
RQ2 and RQ3 ask if the HBM variables mediate the influences of vaccine type and individual characteristics. All significant indirect results are presented in Table 5. Observably, parents showed lower intention to vaccinate their children for monkeypox, compared with COVID-19, through the mediation of safety concerns and risk perception. Participants also showed higher HPV vaccination intention for their children than that of the COVID-19 vaccine, and such effects were mediated by benefit perception and safety concerns. However, perceived susceptibility to the diseases mediated the negative association between the HPV vaccine (compared with the COVID-19 vaccine) and vaccination intention. At the person-level, perceived benefits and barriers mediated all the significant indirect effects. Specifically, they mediated the positive correlation between intention, education, and vaccination history. Black participants, compared to White participants, also showed lower vaccination intention via the mediation of these two variables. The comparison between Asian/Pacific Islander/Native American and White, as well as income, was indirectly related to vaccination intention via the mediation of barrier perception, but the effects were the opposite. Vaccination experience was also positively associated with vaccination intention via the mediation of risk perception.
Table 5.
Significant indirect effects of vaccine type and individual characteristics on vaccination intention.
| Indirect Effects | Maximum likelihood estimate | Bayesian estimate [95 % credibility interval] |
|---|---|---|
| Vaccine-level (within level) indirect effects | ||
| Monkeypox vaccine1 → Safety concern → Vaccination Intention | -0.15*** | -0.16 [−0.22, −0.11] |
| Monkeypox vaccine1 → Perceived susceptibility → Vaccination Intention | -0.50*** | -0.50 [−0.62, −0.39] |
| Monkeypox vaccine1 → Perceived severity → Vaccination Intention | -0.11*** | -0.11 [−0.15, −0.07] |
| HPV vaccine1 → Perceived benefit → Vaccination Intention | 0.14*** | 0.14 [0.07, 0.21] |
| HPV vaccine1 → Safety concern → Vaccination Intention | 0.26*** | 0.25 [0.19, 0.33] |
| HPV vaccine1 → Perceived susceptibility → Vaccination Intention | -0.32*** | -0.32 [−0.40, −0.25] |
| Person-level (between-level) indirect effects | ||
| Black or African American2 → Perceived benefit → Vaccination Intention | -0.27** | -0.30 [−0.54, −0.13] |
| Black or African American2 → Perceived barriers → Vaccination intention | -0.24** | -0.24 [−0.39, −0.11] |
| Asian/Pacific Islander/Native Americans2 → Perceived barriers → Vaccination Intention | -0.21* | -0.2 [−0.41, −0.05] |
| Education → Perceived benefit → Vaccination Intention | 0.05* | 0.05 [0.01, 0.10] |
| Education → Perceived barrier → Vaccination Intention | 0.03* | 0.03 [0.00, 0.06] |
| Income → Perceived barrier → Vaccination Intention | 0.03** | 0.03 [0.01, 0.05] |
| Youngest child’s vaccination experience3→ Perceived benefit → Vaccination Intention | 0.42*** | 0.36 [0.17, 0.64] |
| Youngest child’s vaccination experience3→ Perceived barriers → Vaccination Intention | 0.28*** | 0.23 [0.10, 0.39] |
| Youngest child’s vaccination experience3→ Risk perception → Vaccination Intention | 0.17* | 0.17 [0.05, 0.32] |
Note. 1 Dummy-coded vaccine/disease type variable with COVID-19 as the reference group; 2 Dummy-coded race/ethnicity variable with non-Hispanic White as the reference group; 3 Dummy-coded vaccination experience variable (1 = received all or part of CDC-recommended vaccines for children; 0 = did not receive any CDC-recommended vaccines for children); * p < .05; ** p < .01; *** p < .001
4. Discussion and conclusion
4.1. Discussion
Congruent with existing research on vaccine hesitancy, results from the current research attest to the explanatory power of the HBM in the context of three vaccines, including COVID-19, HPV, and monkeypox vaccines for children. Except for efficacy, all HBM variables were significantly related to participants’ vaccination intention at both the vaccine and person levels. Such a finding may be partly attributable to the enhanced accessibility of vaccines in the U.S. during the COVID-19 pandemic. As parents may have firsthand experience of or have heard about others getting the recent COVID-19 vaccines for children at convenient locations, they may also have higher confidence in their ability to get other vaccines, even when the vaccine is not yet available (e.g., monkeypox vaccines). Consequently, the variance in efficacy perceptions may thus be too small for us to identify a positive effect.
We also found that participants had different views about the three vaccines and their target diseases. Though COVID-19 was once considered a very serious threat, most parents consider it a less severe and probable risk than HPV and monkeypox. Such optimism may be related to the less severe symptoms of the disease among children, and it may also be related to the successful vaccination campaign targeting the diseases. Parents also perceived the COVID-19 vaccine as less beneficial and felt more efficacious in getting the vaccine for their children. Such patterns may indicate that COVID-19 may have become a somewhat trivialized threat, despite its continued influence on people’s health worldwide. Parents were also less likely to consider cost concerns as barriers to vaccinating their children against COVID-19, which may again indicate their familiarity with the freely accessible vaccine. However, it is also notable that they perceived the HPV vaccine as safer than the COVID-19 vaccine, which may be related to the political debates surrounding the latter. The HPV vaccine was also perceived as more beneficial, and HPV infection was perceived as a less probable threat, which may be related to the sexual transmission of the virus and its association with cancer and other severe diseases. Parents’ perception of monkeypox and its vaccine showed high uncertainty. Though they believed that the vaccine was more beneficial, they were not confident they could get it for their children. Parents were also more likely to have safety and cost concerns about the monkeypox vaccine. Notably, they also believed that their children are less susceptible to the less severe disease, which may be due to the association of monkeypox with sexual transmission [35].
The indirect effects of vaccine type on vaccination intention revealed some interesting findings. Risk perception and safety concerns explained the negative association between monkeypox and vaccination intention. As a relatively novel disease, monkeypox is portrayed as impacting mostly adults in mass media, which may render parents less worried about the disease for their children. Similarly, the novelty of the vaccine may also lead to lower vaccination intention. Benefit perception and safety concerns mediated the positive correlation between the HPV vaccine and intention. Considering that HPV vaccines have entered the U.S. market much earlier than the other vaccines and protected many from diseases such as cervical cancer, it is likely that parents may have stronger confidence in its effectiveness and safety, which may contribute to vaccination intention. Differently, perceived susceptibility mediated a negative effect of the HPV vaccine on intention. This is reasonable, considering that HPV infections may not be a very immediate threat to children compared with COVID-19.
At the person-level, perceived barriers and benefits also mediated the effects of some individual characteristics. Parents of color tend to be more skeptical about vaccines’ benefits, safety, and cost, which led to lower vaccination intention. Differently, higher-income and more educated parents whose children have received CDC-recommended vaccines were more likely to get a vaccine for their children due to increased benefit perception and lower behavioral barriers. Such findings indicate that parents’ vaccine decision-making may be heavily influenced by perception of the vaccines, more so than their perception of self-efficacy and risks associated with the diseases. Of note, as the recommended age for HPV and COVID-19 vaccination differ, it is likely that some children were not eligible for the HPV vaccine when they were vaccinated for COVID-19. We did not control age eligibility due to complexity of the multilevel model but included children’s age and history of CDC-recommended vaccines in the models. Relatedly, children’s age may also be related to parents’ perceived distance and mental construal of the vaccines, which may thus influence their considerations of the different vaccines [19]. Nonetheless, improving parents’ understanding of vaccines, particularly their effectiveness and safety, may be an effective strategy to promote child vaccination in the future. However, informing hesitant parents may be insufficient, as vaccine reluctance arises from more than mere unawareness, particularly in anti-vaccine individuals [36]. Persistent endeavors to counteract misinformation and mistrust surrounding vaccinations are crucial.
This study also has limitations. The timely data collection in the U.S. is at the expense of the generalizability of findings. We encourage future studies to investigate the research questions and hypotheses using a more representative sample in diverse sociocultural contexts, including countries with greater access to publicly-funded vaccination programs. Similarly, our focus on mothers also calls for replications of other caregivers, such as fathers. Additionally, future researchers may consider testing the relationships identified here on other vaccines or health behaviors. Further, our HBM-informed hypotheses and research questions were assessed against vaccination intention instead of the actual behavior, which provides the most credible support to the model. Relatedly, though children’s prior vaccine experience was included as a predictor of vaccination intention, we did not assess mothers’ personal or close family vaccination or health history related to the VPDs, which may also influence their intention to vaccinate their children. We thus recommend that future research considers such variables.
4.2. Conclusion
In sum, parents perceived COVID-19, HPV, and monkeypox and their vaccines differently. COVID-19 has been a salient topic in the public discourse in the last few years, but it seems that parents were less concerned about its threat. Correspondingly, their perception of the COVID-19 vaccine may also be trivialized. Considering that the virus may continue to evolve and more people need to get vaccinated, it is important to overcome the possible optimistic bias when persuading parents to vaccinate their children against COVID-19. HPV, on the other hand, is a more familiar vaccine to parents in the U.S. The familiarity further translates into less safety concern and perceived susceptibility. Promotion of the HPV vaccine needs to emphasize the threat of the virus and continue to highlight the safety and effectiveness of the vaccine. Though not available for children at the time of this study, the monkeypox vaccine also caught some parents’ attention. The lack of knowledge of the disease and vaccine seems to create more confusion among parents, which may impede their vaccination intention when the vaccine becomes available. The monkeypox vaccine may not be necessary for children, but future infectious diseases may require vaccination among children. Findings uncovered in the current study again highlight the importance of transparency in communicating novel health threats such as monkeypox. Individual characteristics’ direct and indirect effects also shed light on our understanding of vaccine hesitancy. The lack of confidence in the vaccine’s effectiveness, safety, and accessibility among parents of color may have prevented them from getting a vaccine for their children. The same disparity was also observed among parents with different socioeconomic statuses. Some findings highlight the importance of transparency, particularly in communicating vaccines to underserved populations. Skepticism among lower-income, less-educated, and parents of color toward vaccines requires more attention from public health researchers and practitioners, as we not only need to secure a sufficient supply of vaccines to the underprivileged groups but also convince them about the safety and effectiveness of the vaccines.
4.3. Practice implications
The current study provides valuable guidelines for public health campaigns promoting different vaccines. Specifically, these campaigns need to be tailored according to the type of vaccine and the audience’s characteristics. For novel vaccines targeting emerging diseases, messages need to highlight the severity and susceptibility of the threat while also emphasizing vaccine safety. For vaccines familiar to the target audience, articulating the threats posed by the related diseases may be a more effective strategy to reduce the impacts of optimistic bias. Lastly, campaigns need to focus on underserved populations, such as parents of color and lower socioeconomic status. Improving this group’s understanding of the vaccine’s safety and effectiveness is a more urgent task, as the lack of which may severely impede their intention to get a vaccine for their children or themselves, above and beyond their recognition of the threat of the disease.
CRediT authorship contribution statement
Sixiao Liu: Conceptualization, Methodology, Validation, Formal Analysis, Writing – Original Draft, Writing – Review & Editing. Haoran Chu: Conceptualization, Methodology, Formal Analysis, Resources, Data Curation, Writing – Original draft preparation, Writing – Reviewing and Editing, Visualization.
Declaration of Competing Interest
None.
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