Combination biomedical and behavioral approaches to optimize HIV prevention

The success of biomedical interventions is dependent on behavioral factors affecting medication adherence and treatment uptake

Thirty years after the initial discovery of the virus that causes AIDS, the epidemic continues to spread, both nationally and globally, and it continues to affect millions of individuals across the developmental spectrum (UNAIDS, 2010). Although daunting challenges remain, there have been major advancements in biomedical approaches to reduce HIV transmission during the past 10 years as a result of the increased tolerability and decreased cost of antiretroviral treatment (ART) and vaccines (e.g., Hepatitis B, HPV vaccine), the expanding range of medical options (e.g., male circumcision, microbicides), and the improvement in technological approaches (e.g., female condom). The interest in biomedical approaches has dramatically increased in recent months with the release of findings from the CAPRISA 004 (Karim et al. 2010), the iPrEx (Grant et al., 2010), and the HTPN052 trials (National Institute of Allergy and Infectious Diseases [NIAID], 2011).

South African scientists associated with Caprisa, a Durban-based research center, announced in July 2010 that women who used a vaginal microbicidal gel containing an antiretroviral medication widely used to treat AIDS, tenofovir, were 39 percent less likely overall to contract HIV than those who used a placebo (Weiss, Wasserheit, Barnabas, Hayes, & Abu-Raddad, 2008). Even more impressive, those women who used the gel most regularly reduced their chances of infection 54 percent (Karim et al., 2010). In November 2010, scientists associated with the iPrEx (Pre-exposure Prophylaxis Initiative) trial reported that the HIV infection rate in HIV-negative gay men who were given a daily dose of Truvada (a pill containing two HIV drugs [tenofovir plus FTC]) was reduced by 44 percent, compared with men given a placebo (Grant et al. 2010). In May 2011, results released from the HIV Prevention Trials Network (HPTN) 052 study (NIAID, 2011) indicated that initiation of antiretroviral therapy (ART) reduced transmission from HIV-positive men and women to their seronegative sexual partners by 96 percent.

For many, the results from these three recent studies constitute “game-changing events” suggesting the need to prioritize biomedical over behavioral approaches to HIV prevention. However, close inspection of the results demonstrates that biomedical approaches to HIV prevention are optimized when they are combined with behavioral approaches. Although biomedical approaches to HIV prevention such as “test-linkand- treat strategies” and pre- and postexposure prophylaxis are important tools for HIV prevention, in order to optimize prevention outcomes, they must be combined with evidence-based behavioral strategies including structural interventions that increase access to services, decrease costs, and reduce stigma and discrimination to ensure broadscale implementation (Morin et al., 2011).

The debate over the value of biomedical versus behavioral approaches to HIV prevention has substantial implications for funding decisions about behavioral approaches to HIV prevention and care. In order to promote the value of behavioral approaches to HIV/AIDS and to advocate for ongoing support of both biomedical and behavioral approaches to HIV/AIDS, the Committee on Psychology and AIDS developed the following resolution, which became official APA policy when it was adopted by the Council of Representatives on
February 25, 2012.

Resolution on combination biomedical and behavioral approaches to Optimize HIV prevention

Whereas recent findings from the CAPRISA 004 trials (Karim et al., 2010) (women receiving tenofovir gel were 39 percent less likely to contract HIV than those receiving placebo), the Pre-exposure Prophylaxis Initiative (iPrEx) trials (Grant et al., 2010) (HIV-negative gay men given Truvada had 44 percent lower infection rates than men given placebo), and the HPTN 052 trials (NIAID, 2011) (HIVpositive individuals initiating ART decreased transmission rates to sexual partners by 96 percent) clearly establish the importance of biomedical approaches to HIV prevention, they do not justify decreased focus or funding for behavioral prevention strategies; and,

Whereas these recent biomedical studies represent significant breakthroughs, combination approaches to prevention of HIV and other sexually transmitted infections (STIs) that comprise both biomedical and psychosocial components work best for optimizing health outcomes (Coates, Richter, & Caceres, 2008; Piot, Bartos, Larson, Zewdie, & Mane, 2008); and,

Whereas the success of biomedical interventions is dependent on behavioral factors affecting medication adherence and treatment uptake (i.e., treatment acceptability and use) (Weiss et al. 2008); and,

Whereas the efficacy of the CAPRISA, iPrEX, and HTPN 052 studies were optimized by behavioral approaches (Grant et al., 2010; Karim et al., 2010; NIAID, 2011); and,

Whereas women in the CAPRISA study who accessed the adherence counseling program and used the gel most regularly had an HIV infection rate that was 54 percent lower than controls while those with low adherence had an HIV infection rate that was only 28 percent lower than controls (Karim et al., 2010); and,

Whereas treatment adherence played a central role in the iPrEX study as evidenced by the fact that 91 percent of the men assigned to the treatment group who later tested positive for HIV had no detectable levels of Truvada in their bloodstream (Grant et al., 2010); and,

Whereas behavioral approaches played a central role in the HTPN 052 study (NIAID, 2011), in which all participants were given HIV care that included safe sex counseling; and,

Whereas biomedical interventions for HIV and other STIs without combined behavioral approaches have shown suboptimal medication adherence and treatment uptake (e.g., 80 percent of women do not receive medication to prevent HIV parent-to-child transmission [Temmerman, Quaghebeur, Mwanyumba, & Mandaliya, 2003]; 80 percent of uncircumcised Zambian males have expressed no interest in considering circumcision as an HIV risk-reduction option [based on 2009 qualitative study in Zambia; S. Weiss, personal communication, March 3, 2011]; only 27 percent of drug users in need of the Hepatitis B vaccine completed the required three-dose regimen [McGregor, Marks, Hayward, Bell, & Slack, 2003]; and only 28.2 percent of young women at a clinic who were offered the human papillomavirus vaccine accepted, and of those who accepted, only 55.7 percent completed all three required doses [Moore, Crosby, Yugn, & Chamigo, 2010]); and,

Whereas medication adherence and treatment uptake of biomedical interventions can be addressed by behavioral interventions that enhance knowledge and build skills while incorporating attention to factors such as age, socioeconomic status, religious beliefs, chronic or acute health conditions and disability, developmental understanding, cognitive impairment, race, immigration history and status, language, gender, gender identity, sexual orientation, family context, culture, stigma, mental health, substance abuse, attitudes, prior knowledge, etc. (Liebowitz, Byrnes Parker, & Rotheram-Borus, 2011; Underhill, Operario, Skeer, Mimiaga, & Mayer, 2011); and,

Whereas policy and recommendations have yet to be established as to whether biomedical interventions for HIV prevention will be viewed as life-long or as short-term solutions for high-risk individuals (Paltiel et al., 2009); and, WHEREAS successful behavioral engagement in biomedical prevention models may be out of reach for certain populations (e.g., human trafficking victims, sex workers, people living in poverty, children, etc.) necessitating the development of concurrent models that can be accessed by multiple at-risk populations (Bowleg, Neilands, & Choi, 2008); and,

Whereas there is insufficient behavioral research to assess the potential for unintended consequences and unanticipated ethical issues in everyday clinical use of HIV biomedical interventions (e.g., individuals might engage in more risky behavior; individuals may not use biomedical agents as prescribed; there may be health disparities in access to biomedical interventions; there may be as yet undefined, long-term, negative health implications and side effects from an exclusive reliance on biomedical interventions; etc.);

Therefore behavioral research is needed to optimize medication adherence and treatment uptake, to document real-world decision-making processes associated with biomedical interventions, and to better understand the possible unintended and/or undesired consequences of biomedical interventions; and,

Therefore HIV/STI prevention research teams of the future must bridge biomedical and behavioral approaches and develop new combination approaches that consider biological, cognitive, attitudinal, affective, behavioral, gender, familial, developmental, cultural, educational, social, racial, linguistic, socioeconomic, religious, and environmental factors (Fisher, Smith, & Lenz, 2010; National Institutes of Health, 2011); and,

Therefore funding should be increased for HIV prevention research that incorporates mental health, substance abuse, behavior change, and adherence strategies to optimize the health outcomes of biomedical strategies with special attention paid to the development of combination prevention interventions that can be accessed by multiple at-risk populations; and,

Therefore Congress, the executive branch, state and local governments, and nongovernmental organizations should promote public policies that increase support for multidisciplinary, interdisciplinary and transdisciplinary training, practice, and research; and

Therefore psychology should continue to be mobilized to conduct research on strategies for improving health outcomes based on behavioral optimization of biomedical approaches to HIV/STI prevention and to continue basic and applied research to identify and disseminate effective universal and selective prevention strategies.


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