Posttrial HIV vaccine adoption: concerns, motivators, and intentions among persons at risk for HIV

BACKGROUND: Suboptimal uptake of existing vaccines, potential obstacles specific to HIV/AIDS stigma and mistrust, and marked health disparities suggest that it is vital to investigate consumer concerns, motivations, and adoption intentions regarding posttrial HIV vaccines before a vaccine is publicly available. METHOD: Nine focus groups were conducted with participants (n = 99; median age, 33 years; 48% female; 22% African American, 44% Latino, and 28% white) recruited from 7 high-risk venues in Los Angeles using purposive venue-based sampling. A semistructured interview guide elicited concerns, motivators, and adoption intentions regarding hypothetical U.S. Food and Drug Administration-approved HIV vaccines. Data were analyzed using narrative thematic analysis and Ethnograph qualitative software. RESULTS: Concerns included vaccine efficacy, vaccine-induced infection, vaccine-induced HIV seropositivity, side effects, cost/access, trustworthiness, and relationship issues. Motivators included protection against HIV infection and the ability to safely engage in unprotected sex. Participants expressed reluctance to adopt partial efficacy vaccines and likelihood of increased sexual risk behaviors in response to vaccine availability. CONCLUSION: Tailored interventions to facilitate uptake of future U.S. Food and Drug Administration-approved HIV vaccines and to prevent risk behavior increases may be vital to the effectiveness of vaccines in controlling the AIDS pandemic.     

Predicting the impact of a partially effective HIV vaccine and subsequent risk behavior change on the heterosexual HIV epidemic in low- and middle-income countries: A South African example

We developed a mathematical model to simulate the impact of various partially effective preventive HIV vaccination scenarios in a population at high risk for heterosexually transmitted HIV. We considered an adult population defined by gender (male/female), disease stage (HIV-negative, HIV-positive, AIDS, and death), and vaccination status (unvaccinated/vaccinated) in Soweto, South Africa. Input data included initial HIV prevalence of 20% (women) and 12% (men), vaccination coverage of 75%, and exclusive male negotiation of condom use. We explored how changes in vaccine efficacy and postvaccination condom use would affect HIV prevalence and total HIV infections prevented over a 10-year period. In the base-case scenario, a 40% effective HIV vaccine would avert 61,000 infections and reduce future HIV prevalence from 20% to 13%. A 25% increase (or decrease) in condom use among vaccinated individuals would instead avert 75,000 (or only 46,000) infections and reduce the HIV prevalence to 12% (or only 15%). Furthermore, certain combinations of increased risk behavior and vaccines with <43% efficacy could worsen the epidemic. Even modestly effective HIV vaccines can confer enormous benefits in terms of HIV infections averted and decreased HIV prevalence. However, programs to reduce risk behavior may be important components of successful vaccination campaigns.     

Exploring the relationship of conspiracy beliefs about HIV/AIDS to sexual behaviors and attitudes among African-American adults

Conspiracy beliefs about HIV/AIDS have been endorsed by significant percentages of African Americans in prior research. However, almost no research has investigated the relationship of such beliefs to behaviors and attitudes relevant to HIV risk. In the present exploratory study, 71 African-American adults (aged 18-45; 61% female) in the United States participated in a national, cross-sectional telephone survey examining the relationship of HIV/AIDS conspiracy beliefs to sexual attitudes and behaviors. Results indicated significant associations between endorsement of a general HIV/AIDS government conspiracy and negative beliefs regarding condoms and greater numbers of sexual partners. Endorsement of HIV/AIDS treatment conspiracies was related to positive attitudes about condoms and greater condom use intentions. Findings suggest that conspiracy beliefs have implications for HIV prevention in African-American communities.     

Are HIV/AIDS conspiracy beliefs a barrier to HIV prevention among African Americans?

OBJECTIVES: This study examined endorsement of HIV/AIDS conspiracy beliefs and their relations to consistent condom use and condom attitudes among African Americans. METHODS: We conducted a telephone survey with a random sample of 500 African Americans aged 15 to 44 years and living in the contiguous United States. RESULTS: A significant proportion of respondents endorsed HIV/AIDS conspiracy beliefs. Among men, stronger conspiracy beliefs were significantly associated with more negative condom attitudes and inconsistent condom use independent of selected sociode-mographic characteristics, partner variables, sexually transmitted disease history, perceived risk, and psychosocial factors. In secondary follow-up analyses, men's attitudes about condom use partially mediated the effects of HIV/AIDS conspiracy beliefs on condom use behavior. CONCLUSIONS: HIV/AIDS conspiracy beliefs are a barrier to HIV prevention among African Americans and may represent a facet of negative attitudes about condoms among black men. To counter such beliefs, government and public health entities need to work toward obtaining the trust of black communities by addressing current discrimination within the health care system as well as by acknowledging the origin of conspiracy beliefs in the context of historical discrimination.     

Acceptance of a potential HIV/AIDS vaccine among minority women

PURPOSE: To explore the attitudes, opinions and concerns of minority women regarding acceptance of a potential HIV/ AIDS vaccine. METHODS: In-depth interviews were conducted with high-risk minority women (> or =18 years of age) attending an urban Atlanta health clinic specializing in sexually transmitted diseases, including HIV/AIDS prevention and treatment. Interviews were transcribed and content analyzed to identify common factors related to acceptance of an HIV/AIDS vaccine. RESULTS: Nine major themes were identified. These were general acceptance of an HIV/AIDS vaccine, concerns about the vaccine, vaccine knowledge, testing and research, provider recommendation, mistrust, alternative medicine, misperceptions and vaccine accessibility/availability. A strong theme emerged about the need for information from HIV/AIDS vaccine clinical trials, including the demographics of the studies' volunteer base, to inform decision-making about taking an HIV/AIDS vaccine in the future. CONCLUSIONS: Although fewer than half of the women indicated they would receive or recommend the vaccine, most agreed that development of a vaccine was an important endeavor. The findings of this study may assist in future efforts to determine how best to promote acceptance of an HIV/AIDS vaccine to minority women should one become available.     

Knowledge about vaccines and willingness to participate in preventive HIV vaccine trials: a population-based study, Rakai, Uganda

The purpose of the study was to assess knowledge and beliefs regarding vaccines and willingness to participate in HIV vaccine trials. A baseline survey assessed knowledge and attitudes toward vaccination and potential HIV vaccines among 14,177 participants aged 15-49 years, in a population cohort. Willingness to participate in HIV-preventive vaccine trials was assessed during a follow-up survey 10 months later after providing community education on HIV vaccines. Knowledge of the preventive utility of vaccines was high (71%), but higher in men than women (P<0.001), and increased with education levels (P<0.001). Vaccines were considered appropriate for children and women (99 and 88%, respectively), but not for adult men (28%). Participants felt that adolescents were the most appropriate subjects for HIV preventive vaccine trials (93.7%) but also thought that HIV-positive persons were eligible for trials (60.2%), and only 20% thought a preventive vaccine could help control HIV. HIV vaccine awareness increased from 68% at baseline to 81% at follow-up (P<0.001). Willingness to participate in HIV-preventive vaccine trials was 77%. Vaccine knowledge and willingness to participate in trials are high in this population. However, there still is need for education on the potential role of preventive HIV vaccines in the control of the epidemic and the importance of vaccination for men, especially in the context of an HIV vaccine.     

HIV vaccine trial participation among ethnic minority communities: barriers, motivators, and implications for recruitment

BACKGROUND: Underrepresentation of ethnic minority communities limits the generalizability of HIV vaccine trial results. We explored perceived barriers and motivators regarding HIV vaccine trial participation among low-socioeconomic ethnic minority respondents at risk for HIV. METHODS: Six focus group interviews were conducted using a semistructured interview guide. Participants (N = 58, mean age = 36 years, 37% female, and 56% Latino/a and 35% African American) were recruited using venue-based sampling in Los Angeles. Data were analyzed using narrative thematic analysis and Ethnograph qualitative software. RESULTS: Perceived barriers to HIV vaccine trial participation, in rank order, were (1) vaccine-induced HIV infection, (2) physical side effects, (3) uncertainty about vaccine efficacy, (4) uncertainty about other vaccine characteristics, (5) mistrust, (6) low perceived HIV risk, (7) study demands, (8) stigma, and (9) vaccine-induced HIV seropositivity. Motivators were (1) protection against HIV infection, (2) free insurance and/or medical care, (3) altruism, and (4) monetary incentives. CONCLUSIONS: Population-specific HIV vaccine trial recruitment and implementation strategies should address trial risks from a family perspective, cultural gender norms, mistrust, low perceived HIV risk, the importance of African-American and Latino/a community participation in HIV vaccine trials, and misconceptions about gaining protection against HIV infection. Increasing the cultural relevance of trial recruitment and implementation should facilitate the participation of Latinos/as and African Americans in HIV vaccine trials.     

Antibody responses to Haemophilus influenzae type B vaccines in men with human immunodeficiency virus infection.

BACKGROUND. Persons with human immunodeficiency virus (HIV) infection are at increased risk for serious infections caused by Haemophilus influenzae, yet there are few data on their antibody responses to the H. influenzae type b vaccines. METHODS. We evaluated antibody responses in 248 men who were randomly assigned to receive a single dose of either the H. influenzae type b polysaccharide (PRP) vaccine or the polysaccharide-mutant diphtheria toxoid conjugate vaccine (PRP-CRM). The subjects were stratified into four groups: seronegative men (67 subjects), men with asymptomatic HIV infection (79), men with symptomatic HIV infection (47), and men with the acquired immunodeficiency syndrome (AIDS) (55). RESULTS. Before immunization, the subjects with AIDS had the lowest PRP-antibody titers; 40 percent had titers below the putative protective level (less than 0.15 micrograms per milliliter). In the seronegative subjects, those with asymptomatic HIV infection, and those with symptomatic HIV infection, the PRP-CRM vaccine led to a threefold greater increase in geometric mean antibody titers than did the PRP vaccine (P less than 0.01). However, the subjects with AIDS had a greater antibody response to the PRP vaccine. The antibody response of HIV-seropositive men to the PRP-CRM vaccine correlated significantly with the number of CD4 lymphocytes (r = 0.47, P less than 0.0001, as compared with r = -0.01 for the PRP vaccine). In these HIV-infected men, both vaccines elicited the dominant anti-PRP idiotype described previously in populations not infected with HIV. CONCLUSIONS. Immunization with the PRP-CRM conjugate vaccine early in the course of HIV infection is likely to confer protection against disease caused by H. influenzae type b.     

“There is no proof that HIV causes AIDS”: AIDS denialism beliefs among people living with HIV/AIDS

AIDS denialists offer false hope to people living with HIV/AIDS by claiming that HIV is harmless and that AIDS can be cured with natural remedies. The current study examined the prevalence of AIDS denialism beliefs and their association to health-related outcomes among people living with HIV/AIDS. Confidential surveys and unannounced pill counts were collected from a convenience sample of 266 men and 77 women living with HIV/AIDS that was predominantly middle-aged and African American. One in five participants stated that there is no proof that HIV causes AIDS and that HIV treatments do more harm than good. AIDS denialism beliefs were more often endorsed by people who more frequently used the internet after controlling for confounds. Believing that there is a debate among scientists about whether HIV causes AIDS was related to refusing HIV treatments and poorer health outcomes. AIDS denialism beliefs may be common among people living with HIV/AIDS and such beliefs are associated with poor health outcomes.     

Determinants of enrollment in a preventive HIV vaccine trial: hypothetical versus actual willingness and barriers to participation

OBJECTIVE: To compare hypothetical and actual willingness to enroll in a preventive HIV vaccine trial and identify factors affecting enrollment. METHODS: Participants previously enrolled in an HIV vaccine preparedness study (VPS) in 8 US cities were invited to be screened for a phase 2 HIV vaccine trial. Demographic and risk characteristics of those enrolling, ineligible, and refusing enrollment were compared using the chi2 or Fisher exact test. Multivariable logistic models were used to identify independent predictors of refusal. RESULTS: Of 2531 high-risk HIV-uninfected former VPS participants contacted for the vaccine trial, 13% enrolled, 34% were ineligible, and 53% refused enrollment. Only 20% of those stating hypothetical willingness during the VPS actually enrolled in this vaccine trial. In multivariate analysis, refusal was higher among African Americans and lower in persons >40 years of age, those attending college, and those with > or =5 partners in the prior 6 months. All racial ethnic groups cited concerns about vaccine-induced seropositivity; African Americans also cited mistrust of government and safety concerns as barriers to enrollment. CONCLUSIONS: Steps can be taken to minimize potential social harms and to mobilize diverse communities to enroll in trials. Statements of hypothetical willingness to participate in future trials may overestimate true enrollment.     

Who will enroll? Predicting participation in a phase II AIDS vaccine trial.

BACKGROUND: The problems of underenrollment and selective enrollment may undermine AIDS vaccine trials. If prospective study subjects' stated willingness to participate (WTP) in hypothetical vaccine trials predicts future enrollment, then measuring WTP before recruitment may enhance the enrollment in, and ethics of, such trials. METHODS: We prospectively studied changes over an 18-month period in the stated WTP in, and knowledge of, a hypothetical AIDS vaccine trial among 610 Philadelphia residents at high risk for HIV infection. Of these people, 499 were subsequently recruited to participate in an actual, phase II AIDS vaccine trial. We used multivariable logistic regression and the area under the receiver-operating characteristic (ROC) curve to model predictors of actual enrollment. RESULTS: Actual enrollment rates were 8.3%, 6.8%, 15.8%, and 29.0% among those who had initially said they were "definitely not," "probably not," "probably," and "definitely" willing to participate, respectively (p =.006). The area under the ROC curve was 0.65, indicating a modest ability of stated WTP to differentiate those who enroll from those who do not. Knowledge of basic vaccine trial concepts, though unrelated to enrollment, increased over an 18-month period with repeated education sessions (p <.0001), whereas stated WTP declined over this same period (p <.0001). CONCLUSION: Although other factors not captured by stated WTP may also influence future enrollment, prospectively assessing stated WTP may augment the validity of the informed consent process, help prevent underenrollment, and clarify the population from which the study sample is drawn.     

Developing AIDS vaccine trials educational programs in Uganda

In preparation for HIV vaccine trials, data on a cohort's knowledge about vaccines and vaccine studies are required so as to tailor educational materials to adequately meet local needs. Interviews (n = 1,182) conducted as part of a 3-year prospective study of Ugandan military men aged 18 to 30 years determined what information, in addition to standard trials information, would be required to ensure comprehension of trial procedures. The interviews highlighted four points: (1) the cohort has a lot of knowledge about vaccines but conflates whether vaccines cure or prevent disease; (2) there is a general lack of knowledge about clinical trials procedures; (3) the desire to be protected from HIV/AIDS is a common reason for being willing to participate in a hypothetical vaccine trial; and (4) concern about side effects is a common reason for being unwilling to participate in a trial. These four points guided the focus of the vaccine trials education, which used locally appropriate analogies to introduce complex unfamiliar concepts such as placebos and blinding. This case study highlights the value of incorporating baseline interviews to assess the educational needs of study populations.     

Polio vaccines and the origin of AIDS

Although mass vaccination programs have resulted in the eradication of a number of human infectious diseases, vaccine contamination has been a persistent concern. In particular, it is now known that the early polio vaccines were contaminated with at least one monkey virus, SV40. The transfer of monkey viruses to man via contaminated vaccines is particularly relevant to the acquired immunodeficiency syndrome (AIDS), since the causative agent of AIDS, human immunodeficiency virus (HIV), is thought to be derived from a simian precursor virus. Furthermore, human infection with this virus appears to be a relatively recent event. We hypothesize that the AIDS pandemic may have originated with a contaminated polio vaccine that was administered to inhabitants of Equatorial Africa from 1957 to 1959. The mechanism of evolution of HIV from this vaccine remains to be determined.     

Assessing the attitudes, knowledge, and awareness of HIV vaccine research among adults in the United States

OBJECTIVES: To assess HIV vaccine research attitudes, awareness, and knowledge among adults in the general US population, African Americans, Hispanics, and men who have sex with men (MSM). METHODS: Applying results of focus groups and a media content analysis, a survey was designed and conducted to validate key HIV vaccine research themes and messages identified by focus groups and a media content analysis. Between December 2002 and February 2003, 3509 telephone interviews were conducted, including 2008 randomly selected from the general population, and 501 population-specific samples of African Americans and Hispanics, and 500 from MSM. RESULTS: Although the majority of each population believes that an HIV preventive vaccine is the best way to control and end the global AIDS epidemic, only 34.9% of African Americans and 28.8% of the general population are supportive of someone they know volunteering for an HIV vaccine trial. The study also found that 47.1% of African Americans, 26.5% of Hispanics, and 13.4% of MSM believed an HIV vaccine already exists and is being kept secret, and 78.0% of African Americans, 57.5% of Hispanics, and 68.0% of MSM did not know or incorrectly believed that the vaccines being tested could cause HIV infection. A subanalysis of the general population also found that women generally had less knowledge of or a decreased awareness about HIV vaccine research. CONCLUSIONS: Awareness, knowledge, and attitudes toward HIV vaccine research vary by population and these issues must be addressed to ensure an adequate number of volunteers for future domestic HIV preventive vaccine clinical trials. In some populations, barriers such as misinformation and distrust must be targeted to increase support for HIV vaccine research.     

Building collaborative networks for HIV/AIDS vaccine development: the AVIP experience

The need for an effective HIV/AIDS vaccine is imperative to halt a pandemic that involves more than 40 million individuals worldwide as of 2005 and is causing enormous socio-economic losses, especially in developing countries (DC). The overall failure of more than two decades of HIV vaccine research justifies the demands for a concerted effort for the rapid development of new and efficacious vaccines against HIV/AIDS. In this context, building international collaborative networks is a must for speeding up scientific research and optimizing the use of funding in a synergistic fashion, as resources for HIV/AIDS are limited and do not involve most of the biggest Pharmas that are more interested in drug discovery. The AIDS Vaccine Integrated Project (AVIP) consortium is an example of synergistic partnership of international European Union and DC experts with a common research goal. AVIP is a European Commission-funded (FP-6), consortium-based, 5-year program directed to the fast development of new HIV/AIDS vaccine candidates to be tested in phase I clinical trials in Europe for future advancement to phase II/III testing in DC. To ensure their rapid development, AVIP novel combined vaccines include both regulatory and structural HIV antigens, which have already been tested, as single components, in phase I clinical trials. In particular, such combination vaccines may be superior to earlier vaccine candidates, the vast majority of which are based only on either structural or regulatory HIV products. In fact, the generation of immune responses to both types of viral antigens expressed either early (regulatory products) or late (structural products) during the viral life cycle can maximize immune targeting of both primary or chronic viral infection. Further, the rational design of combined vaccines allows exploitation of immunomodulatory functions of HIV regulatory proteins, which can improve immunity against structural vaccine components. The building of the AVIP consortium and its scientific strategy will be reviewed in this paper as an example of the establishment of a consortium regulated by a specific intellectual property agreement.     

HIV Treatment Beliefs and Sexual Transmission Risk Behaviors among HIV Positive Men and Women

People are living longer and healthier with HIV infection because of successful combination antiretroviral therapies. HIV treatment beliefs are often associated with sexual practices among people living with HIV/AIDS but these associations may depend on the HIV status of sex partners. In a sample of 158 HIV positive men and women who were receiving HIV treatments, we examined the association between HIV treatment beliefs, HIV transmission risk perceptions, medication adherence, viral load and engaging in unprotected intercourse with any sex partners and specifically with sex partners who were not HIV positive (non-concordant). Results showed having missed medications in the past two days and treatment-related beliefs were significantly associated with engaging in unprotected intercourse with all sex partners as well as non-concordant partners. However, multivariate models showed that only treatment beliefs were significantly associated with engaging in unprotected intercourse with non-concordant partners. These results extend past research by demonstrating that the HIV status of sex partners sets the context for whether prevention-related treatment beliefs are associated with HIV transmission risk behaviors among people living with HIV/AIDS.     

Family communication about HIV/AIDS and sexual behaviour among senior secondary school students in Accra,Ghana

Background

Sexually active adolescents in Ghana are increasingly at risk of HIV and other sexually transmitted infections. As a primary agent of socialization, the family can exert a strong influence on adolescent sexual behaviour. Therefore, to aid in the design and implementation of effective prevention programmes, it is important to understand the role of the family in influencing sexual behaviour among school-going adolescents.

Objectives

To evaluate the relationship between family communications about HIV/AIDS and sexual activity and condom use among school-going adolescents in Accra, Ghana.

Method

A sample of 894 students (56.9% girls, 43.1% boys; mean age = 17.4 years, SD = 1.40) at two senior secondary schools in Accra completed a modified version of the Youth Risk Behavior Survey (YRBS) questionnaire, a self-administered instrument developed by the Centers for Disease Control and Prevention. Analytical techniques utilized included logistic regression and chisquare.

Results

Twenty-five percent of the participants reported being sexually experienced, and 73.6% had talked about HIV/AIDS with parents or other family members. Of the sexually experienced students, 64.7% initiated first sexual intercourse by age 16; and 55.7% did not use a condom at last sexual intercourse. Bivariate analysis showed significant gender differences in sexual activity, condom use, and family communication about HIV/AIDS. Logistic regression analysis showed that student-family communication about HIV/AIDS was not associated with sexual activity. However, communication about HIV/AIDS between students and parents or other family members increased the odds of using a condom at last sexual intercourse.

Conclusions

The findings of this study suggest that prevention programmes that seek to educate Ghanaian school-going adolescents about sexual risk behaviour must strongly encourage communication about HIV/AIDS between students and family members.     

How much protection is enough?

The debate on preventive HIV vaccines at the International AIDS Conference made global economic differences visible. The typical cost of $15,000 per year to treat AIDS patients is beyond the reach of 90 percent of the world's HIV population, most of whom live in Africa and Asia. However, no vaccine developed to date has been worthy of wide-scale testing, but about 25 vaccines are in phase-1 safety testing worldwide. There are many ethical concerns with testing HIV viruses because it is likely that volunteers will be infected in the testing process.     

Use of Nonhuman Primate Models to Develop Mucosal AIDS Vaccines

The HIV vaccines tested in the halted Step efficacy trial and the modestly successful phase 3 RV144 trial were designed to elicit strong systemic immune responses; therefore, strategies to direct immune responses into mucosal sites should be tested in an effort to improve AIDS vaccine efficacy. However, as increased CD4⁺ T-cell activation and recruitment to mucosal sites have the potential to enhance HIV transmission, mucosal immune responses to HIV vaccines should primarily consist of effector CD8⁺ T cells and plasma cells. Controlling the level of mucosal T-cell activation may be a critical factor in developing an effective mucosal AIDS vaccine. Immunization routes and adjuvants that can boost antiviral immunity in mucosal surfaces offer a reasonable opportunity to improve AIDS vaccine efficacy. Nonhuman primate models offer the best system for preclinical evaluation of these approaches.     

Vaccine approaches currently in development

The need for a vaccine against HIV/AIDS is becoming vital since the cost of treating the disease is making many poorer countries unable to provide widely-available therapies to their populations. Obstacles to vaccine development include lack of understanding by researchers on what constitutes immunity against HIV infection, the highly variable nature of HIV, and the lack of an ideal animal model to test HIV vaccines. The following vaccine approaches, which are currently in development, are discussed: subunit vaccines (gp120 vaccines), recombinant vector vaccines, prime boost regimens, DNA vaccines, whole-killed vaccines, live-attenuated vaccines, virus-like particle vaccines, and peptide vaccines. The progress being made in vaccine development is slow, but steady. However, none of the approaches appear ready for large-scale human trials. The growing realization that a vaccine is needed may lead to more substantial funding and greater progress in developing a vaccine.