Exposure to immunization media messages among African American parents

Attitudinal analysis of vaccination effects to lead endemic phases

To achieve endemic phases, repeated vaccinations are necessary. However, individuals may grapple with whether to get vaccinated due to potential side effects. When an individual is already immune due to previous infections or vaccinations, the perceived risk from vaccination is often less than the risk of infection. Yet, repeated rounds of vaccination can lead to avoidance, impeding the establishment of endemic phases. We explore this phenomenon using an individual-based Monte Carlo simulation, validating our findings with game theory. The Nash equilibrium encapsulates individuals' non-cooperative behavior, while the system's optimal value represents the societal benefits of altruistic cooperation. We define the difference between these as the price of anarchy. Our simulations reveal that the price of anarchy must fall below a threshold of 12.47 for endemic phases to be achieved in a steady state. This suggests that for a basic reproduction number of 10, a consistent vaccination rate greater than 89% is required. These findings offer new insights into vaccination-related decision-making and can inform effective strategies to tackle infectious diseases.

Multimodal Counseling Interventions: Effect on Human Papilloma Virus Vaccination Acceptance

Human papilloma virus (HPV) vaccine was developed to reduce HPV-attributable cancers, external genital warts (EGW), and recurrent respiratory papillomatosis. Adolescent HPV vaccination series completion rates are less than 40% in the United States of America, but up to 80% in Australia and the United Kingdom. Population-based herd immunity requires 80% or greater vaccination series completion rates. Pro-vaccination counseling facilitates increased vaccination rates. Multimodal counseling interventions may increase HPV vaccination series non-completers’ HPV-attributable disease knowledge and HPV-attributable disease prophylaxis (vaccination) acceptance over a brief 14-sentence counseling intervention. An online, 4-group, randomized controlled trial, with 260 or more participants per group, found that parents were more likely to accept HPV vaccination offers for their children than were childless young adults for themselves (68.2% and 52.9%). A combined audiovisual and patient health education handout (PHEH) intervention raised knowledge of HPV vaccination purpose, p = 0.02, and HPV vaccination acceptance for seven items, p < 0.001 to p = 0.023. The audiovisual intervention increased HPV vaccination acceptance for five items, p < 0.001 to p = 0.006. That HPV causes EGW, and that HPV vaccination prevents HPV-attributable diseases were better conveyed by the combined audiovisual and PHEH than the control 14-sentence counseling intervention alone.

Multicomponent interventions to enhance influenza vaccine delivery to adolescents

OBJECTIVE

To compare school- versus provider-based approaches to improving influenza vaccination coverage among adolescents in rural Georgia.

METHODS

We used a nonrandomized, 3-armed design: (1) a middle- and high school-based influenza vaccination intervention in 1 county; (2) a provider-based influenza vaccination intervention in a second county; and (3) a standard-of-care condition in a third county. Interventions also included distribution of an educational brochure, school presentations, and community-based outreach to enhance vaccine knowledge and awareness among adolescents and their parents.

RESULTS

During the 2008-2009 influenza season, 70 (19%) of 370 students were vaccinated in the school-based county and 110 (15%) of 736 students were vaccinated in the provider-based county, compared with 71 (8%) of 889 students in the standard-of-care county (risk ratio [RR](school): 2.4 [95% confidence interval (CI): 1.7-3.2]; RR(provider): 1.9 [95% CI: 1.4-2.5]). During 2009-2010, seasonal influenza vaccination coverage was 114 (30.4%) of 375 of students in the school-based county, 122 (16.9%) of 663 of students in the provider-based county, and 131 (15.2%) of 861 students in the standard-of-care county (RR(school): 2.3 [95% CI: 1.9-2.9]; RR(provider): 1.2 [95% CI: 0.97-1.5]).

CONCLUSIONS

Special efforts to promote influenza vaccination among rural, predominantly black students were associated with increased vaccination coverage. The school-based influenza vaccination intervention was associated with the highest levels of vaccination coverage. This study revealed the efficacy of school-based influenza education to improve vaccination rates among adolescents.

Psychosocial correlates of intention to receive an influenza vaccination among rural adolescents

The Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices recently expanded annual influenza vaccination recommendations to include all children 6 months through 18 years of age. Adolescent attitudes toward influenza vaccination may play a key role in reaching this newly added age group. This study examined the association between attitudes toward influenza vaccination and intention to be vaccinated among rural adolescents. Data were collected from baseline surveys distributed to adolescents in September/October 2008, prior to the H1N1 influenza pandemic, in two counties participating in a school-based influenza vaccination intervention trial in rural Georgia (N = 337). Survey items were based on constructs from the Health Belief Model and the Integrated Behavioral Model. Approximately one-third of participants (33.8%) intended to receive an influenza vaccination, 33.5% did not intend to be vaccinated and 28.8% were unsure. Controlling for background factors, intention to receive an influenza vaccination was associated with low perceived barriers [odds ratio (OR) = 0.77, P < 0.001], injunctive norms (OR = 1.23, P = 0.002) and receipt of influenza vaccination in the past year (OR =6.21, P < 0.001). Findings suggest that perceived barriers and injunctive social norms may influence vaccination acceptance among rural adolescents. Future influenza vaccination efforts geared toward rural middle and high school students may benefit from addressing adolescent attitudes toward influenza vaccination.

Effectiveness of a social marketing media campaign to reduce oral cancer racial disparities

OBJECTIVES

The purpose of this study was to provide a systematic evaluation of a theory-driven oral cancer awareness media campaign.

METHODS

We surveyed a cohort of residents in an intervention city (250) and a control city (250) immediately prior to and after the media campaign. Participants (125 black/African American and 125 white) in each city completed surveys at baseline and follow-up. Oral cancer campaign awareness was assessed in both cities, along with 4 hypothetical health campaigns. Oral cancer awareness, oral cancer exam awareness, intent to receive an oral cancer exam, interest in exam, and receipt of exam were also assessed in both cities, both at baseline and follow-up.

RESULTS

Intervention city residents showed a significant increase in recognition of the campaign, awareness of the oral cancer exam, and interest in getting an exam, while no significant changes in those topics were found for the control city. Blacks/African Americans in the intervention city were significantly more likely than whites to demonstrate increases in awareness of the campaign, oral cancer awareness, and interest in receiving an oral cancer exam.

CONCLUSIONS

A theory-driven media campaign was successful in increasing awareness of the oral cancer exam and interest in the exam among blacks/African Americans.

Promoting HIV risk awareness and testing in Latinos living on the U.S.-Mexico border: the Tú No Me Conoces social marketing campaign

Increased incidence of HIV/AIDS in Latinos warrants effective social marketing messages to promote testing. The Tú No Me Conoces (You Don't Know Me) social marketing campaign promoted awareness of HIV risk and testing in Latinos living on the California-Mexico border. The 8-week campaign included Spanish-language radio, print media, a Web site, and a toll-free HIV-testing referral hotline. We documented an increase in HIV testing at partner clinics; 28% of testers who heard or saw an HIV advertisement specifically identified our campaign. Improved understanding of effective social marketing messages for HIV testing in the growing Latino border population is warranted.

Dynamics of Vaccination Strategies via Projected Dynamical Systems

Previous game theoretical analyses of vaccinating behaviour have underscored the strategic interaction between individuals attempting to maximise their health states, in situations where an individual's health state depends upon the vaccination decisions of others due to the presence of herd immunity. Here, we extend such analyses by applying the theories of variational inequalities (VI) and projected dynamical systems (PDS) to vaccination games. A PDS provides a dynamics that gives the conditions for existence, uniqueness and stability properties of Nash equilibria. In this paper, it is used to analyse the dynamics of vaccinating behaviour in a population consisting of distinct social groups, where each group has different perceptions of vaccine and disease risks. In particular, we study populations with two groups, where the size of one group is strictly larger than the size of the other group (a majority/minority population). We find that a population with a vaccine-inclined majority group and a vaccine-averse minority group exhibits higher average vaccine coverage than the corresponding homogeneous population, when the vaccine is perceived as being risky relative to the disease. Our model also reproduces a feature of real populations: In certain parameter regimes, it is possible to have a majority group adopting high vaccination rates and simultaneously a vaccine-averse minority group adopting low vaccination rates. Moreover, we find that minority groups will tend to exhibit more extreme changes in vaccinating behaviour for a given change in risk perception, in comparison to majority groups. These results emphasise the important role played by social heterogeneity in vaccination behaviour, while also highlighting the valuable role that can be played by PDS and VI in mathematical epidemiology.

Determinants of influenza vaccination in hard-to-reach urban populations

OBJECTIVE

Influenza vaccination rates among disadvantaged minority and hard-to-reach populations are lower than in other groups. We assessed the barriers to influenza vaccination in disadvantaged urban areas.

METHODS

We conducted a cross-sectional study, using venue-based sampling, collecting data on residents of eight neighborhoods throughout East Harlem and the Bronx, New York City.

RESULTS

Of 760 total respondents, 461 (61.6%) had received influenza vaccination at some point in their life. In multivariable models, having access to routine medical care, receipt of health or social services, having tested positive for HIV, and current interest in receiving influenza vaccination were significantly associated with having received influenza vaccination in the previous year. Of participants surveyed, 79.6% were interested in receiving an influenza vaccination at the time of survey. Among participants who had never previously received influenza vaccination in the past, 73.4% were interested in being vaccinated; factors significantly associated with an interest in being vaccinated were minority race, lower annual income, history of being homeless, being uninsured/underinsured, and not having access to routine medical care.

CONCLUSIONS

Participants who are unconnected to health or social services or government health insurance are less likely to have been vaccinated in the past although these persons are willing to receive vaccine if it were available.

Understanding and overcoming barriers to human papillomavirus vaccine acceptance

New vaccines designed to prevent human papillomavirus (HPV) infection have the potential to reduce the incidence of serious illness and death worldwide among women, substantially reduce the emotional suffering associated with abnormal Papanicolaou (Pap) test results and the diagnosis of cervical cancer, and save significant health care dollars. However, these benefits may not be fully realized until the vaccine is accepted by patients, parents, and health care practitioners. Furthermore, there may be unique issues related to the acceptance of a vaccine designed to prevent a sexually transmitted infection that is poorly understood by many women. Among the acceptance issues are: individual comfort with a sexually transmitted infection (STI) vaccine; parental comfort with vaccination of their preadolescent/early adolescent daughters; physician comfort with recommending a human papillomavirus vaccine to women and parents of preadolescents; and physician communication skills related to talking with women and parents about the vaccine. Potentially difficult as it might be to implement a vaccination program, vaccination and prevention of HPV-associated disease are still infinitely preferable to observation and treatment. This article will review some of the potential barriers to HPV Vaccine acceptance, with a particular focus on factors relevant to female patients, parents, and health care providers.

Imitation dynamics predict vaccinating behaviour

There exists an interplay between vaccine coverage, disease prevalence and the vaccinating behaviour of individuals. Moreover, because of herd immunity, there is also a strategic interaction between individuals when they are deciding whether or not to vaccinate, because the probability that an individual becomes infected depends upon how many other individuals are vaccinated. To understand this potentially complex interplay, a game dynamic model is developed in which individuals adopt strategies according to an imitation dynamic (a learning process), and base vaccination decisions on disease prevalence and perceived risks of vaccines and disease. The model predicts that oscillations in vaccine uptake are more likely in populations where individuals imitate others more readily or where vaccinating behaviour is more sensitive to changes in disease prevalence. Oscillations are also more likely when the perceived risk of vaccines is high. The model reproduces salient features of the time evolution of vaccine uptake and disease prevalence during the whole-cell pertussis vaccine scare in England and Wales during the 1970s. This suggests that using game theoretical models to predict, and even manage, the population dynamics of vaccinating behaviour may be feasible.

Improving adolescent health: focus on HPV vaccine acceptance

The success of future human papillomavirus (HPV) vaccination programs will depend on individuals' willingness to accept vaccination, parents' willingness to have their preadolescent and early adolescent children vaccinated, and health care providers' willingness to recommend HPV vaccination. The purpose of this article is to provide a qualitative review of the relevant literature, including research on knowledge and attitudes about HPV infection and its clinical sequelae, the acceptability of HPV vaccination to individuals and parents, and health care providers' attitudes about recommending HPV vaccination. Additionally, strategies are suggested by which providers of adolescent health care can discuss and recommend HPV vaccines with parents and their children. The research published to date suggests that there is a good deal of misunderstanding about HPV infection, cervical cancer screening, and the sequelae of HPV infection. However, the majority of research studies to date indicate that young women, parents, and health care providers are interested in vaccines that prevent HPV and other sexually transmitted infections (STIs). Of particular note are the consistent findings that providers are less comfortable vaccinating younger versus older adolescents and that endorsement of vaccination by a professional organization is of great importance. Furthermore, research suggests that most parents are interested in having their preadolescent and adolescent children vaccinated against HPV. Parents value the information and recommendations provided by their children's health care providers. To the extent that providers are concerned about potential negative reactions of parents to a recommendation of HPV vaccination, these findings should provide reassurance. At the same time, health care providers will need to be prepared to provide patients and parents with information about HPV and HPV immunization and to respond productively to the rare parent who expresses opposition to HPV vaccine or any other vaccine.

Vaccination and the theory of games

Voluntary vaccination policies for childhood diseases present parents with a subtle challenge: if a sufficient proportion of the population is already immune, either naturally or by vaccination, then even the slightest risk associated with vaccination will outweigh the risk from infection. As a result, individual self-interest might preclude complete eradication of a vaccine-preventable disease. We show that a formal game theoretical analysis of this problem leads to new insights that help to explain human decision-making with respect to vaccination. Increases in perceived vaccine risk will tend to induce larger declines in vaccine uptake for pathogens that cause more secondary infections (such as measles and pertussis). After a vaccine scare, even if perceived vaccine risk is greatly reduced, it will be relatively difficult to restore prescare vaccine coverage levels.

Differential willingness to undergo smallpox vaccination among African-American and white individuals

OBJECTIVE

To examine potential disparities in willingness to be vaccinated against smallpox among different U.S. racial/ethnic groups.

DESIGN

Cross-sectional survey using an experimental design to assess willingness to be vaccinated among African Americans compared to whites according to 2 strategies: a post-exposure "ring vaccination" method and a pre-exposure national vaccination program.

SETTING

Philadelphia County district courthouse.

PARTICIPANTS

Individuals awaiting jury duty.

MEASUREMENTS

We included 2 scenarios representing these strategies in 2 otherwise identical questionnaires and randomly assigned them to participants. We compared responses by African Americans and whites.

MAIN RESULTS

In the pre-exposure scenario, 66% of 190 participants were willing to get vaccinated against smallpox. In contrast, 84% of 200 participants were willing to get vaccinated in the post-exposure scenario (P =.0001). African Americans were less willing than whites to get vaccinated in the pre-exposure scenario (54% vs 77%; P =.004), but not in the post-exposure scenario (84% vs 88%; P =.56). In multivariate analyses, overall willingness to undergo vaccination was associated with vaccination strategy (odds ratio, 3.29; 95% confidence interval, 1.8 to 6.1).

CONCLUSIONS

Racial disparity in willingness to get vaccinated varies by the characteristics of the vaccination program. Overall willingness was highest in the context of a post-exposure scenario. These results highlight the importance of considering social issues when constructing bioterror attack response plans that adequately address the needs of all of society's members.

Correlates of parental antibiotic knowledge, demand, and reported use

BACKGROUND

Clinicians cite parental misconceptions and requests for antibiotics as reasons for inappropriate prescribing.

AIMS

To identify misconceptions regarding antibiotics and predictors of parental demand for antibiotics and to determine if parental knowledge and attitudes are associated with use.

METHODS

Survey of parents in 16 Massachusetts communities. Domains included antibiotic-related knowledge, attitudes about antibiotics, antibiotic use during a 12-month period, demographics, and access to health information. Bivariate and multivariate analyses evaluated predictors of knowledge and proclivity to demand antibiotics. A multivariate model evaluated the associations of knowledge, demand, and demographic factors with parent-reported antibiotic use.

RESULTS

A total of 1106 surveys were returned (response rates: 54% and 32% for commercially-insured and Medicaid-insured families). Misconceptions were common regarding bronchitis (92%) and green nasal discharge (78%). Two hundred sixty-five (24%) gave responses suggesting a proclivity to demand antibiotics. Antibiotic knowledge was associated with increased parental age and education, having more than 1 child, white race, and receipt of media information on resistance. Factors associated with a proclivity to demand antibiotics included decreased knowledge, pressure from day-care settings, lack of alternatives offered by clinicians, and lack of access to media information. Among all respondents, reported antibiotic use was associated with younger child age and day-care attendance. Among Medicaid-insured children only, less antibiotic knowledge and tendency to demand antibiotics were associated with higher rates of antibiotic use.

CONCLUSIONS

Misconceptions regarding antibiotic use are widespread and potentially modifiable by clinicians and media sources. Particular attention should be paid to Medicaid-insured patients in whom such misconceptions may contribute to inappropriate prescribing.