FL: HIV, 1 unitPage 8 of 11

6. Prevention of HIV Infection

Many are seeking to address the HIV epidemic through prevention programs. These efforts include national, international, and local programs. A bright spot on the horizon is the possibility of a vaccine.

Potential Vaccine in the Pipeline

As noted in the bulletin at the top of the course, there is growing confidence that in the future a vaccine for HIV may be able to “remove the HIV virus from the body.” For a video issued in September 2013 by Louis Picker, associate director of the Oregon Health and Science University’s Vaccine and Gene Therapy Institute, click here.

National HIV/AIDS Strategy

A conservative estimate for the period 1991 to 2006 finds that in the United States prevention has already averted more than 350,000 HIV infections. The nation’s HIV prevention efforts are guided by a single, ambitious strategy for combating the epidemic: the National HIV/AIDS Strategy (NHAS). Recent scientific breakthroughs and growing leadership and momentum among some of the hardest hit communities bode well for change (CDC, 2013e).

To address the continuing challenges, CDC and its partners are pursuing a High-Impact Prevention approach to reducing new HIV infections. High-Impact Prevention refers to use of combinations of scientifically proven, cost-effective, and scalable interventions targeted to the right populations in the right geographic areas, and is intended to increase the impact of HIV prevention efforts—an essential step in achieving the goals of NHAS (CDC, 2013e).

This approach is designed to maximize the impact of prevention efforts for all Americans at risk for HIV infection, including gay and bisexual men, communities of color, women, injection drug users, transgender women and men, and youth (CDC, 2013e).

Behavior Change for HIV Prevention

In instances where national epidemics have been reversed, a number of evidence-based studies have shown that broad-based behavioral changes were central to success. A comprehensive review of the evidence documents both the efficacy (the impact seen in a clinical trial setting) and the effectiveness (the impact seen in real-world settings) of behavioral HIV prevention efforts. Hundreds of randomized controlled trials have demonstrated that individual, small group, and community-level interventions can generate safer behaviors (Working Group, 2008).

Studies in low- and middle-income countries among young people, sex workers, and other populations have demonstrated that prevention programs have the ability to change sexual and drug-use behaviors in resource-limited settings and prevent HIV transmission. The prevention programs have used the following evidence-based approaches to prevent HIV infection:

  • Programs target individual behavior.
  • Emphasis is on broad-based efforts to alter social norms and address the underlying drivers of the epidemic.

In addition, there is effective use of available tools such as:

  • Treatment of sexually transmitted infections (STIs)
  • Medical male circumcision
  • Substitution therapy for chemical dependence
  • Programs that provide access to clean injecting equipment (Working Group, 2008)

Using these and other interventions aimed at behavioral change, several countries have had dramatic successes in curbing the spread of HIV within their borders:

  • In Brazil, public health campaigns have encouraged open discussion of HIV, frank public-awareness campaigns, condom promotion, focused behavioral interventions, syringe and needle exchange, school-based HIV education, prevention services in prisons, and voluntary HIV counseling and testing. Especially noteworthy is Brazil’s success in reversing a serious epidemic among injection drug users. Condom use increased by almost 50% among sexually active adults between 1998 and 2005, and focused behavioral change prevention programs also maintained HIV prevalence at low levels among sex workers. Although the World Bank had predicted in 1990 that 1.2 million Brazilians would be infected by 2000, fewer than 600,000 were living with HIV in 2002.
  • In Australia, broad public-awareness campaigns have focused on behavioral interventions among gay men, syringe exchange programs, and voluntary counseling and testing for HIV. As a result of Australia’s early, comprehensive response, focused largely on behavior change, annual HIV incidence peaked in 1985 and declined through the end of the 1990s. Between 1990 and 2000, the annual number of new HIV diagnoses fell by half.
  • In what is perhaps the world’s best-documented national prevention success, Uganda moved in the mid-1980s to address the rapid spread of HIV, implementing public-awareness campaigns that encouraged young people to delay initiation of sex and urged sexually active adults to reduce the number of sex partners. In the 1990s, the country supplemented these early measures with condom promotion and investment in voluntary counseling and testing.
  • From the earliest years, community-generated programs played a major role in the country’s AIDS response. The results of these efforts were remarkable. The percentage of young people who were sexually active fell by more than half between 1989 and 1995, and Ugandans were significantly less likely to have multiple sex partners than people living in neighboring countries. Increases in condom use in the 1990s helped preserve and accelerate early prevention gains. By the late 1990s, infection levels in capital city Kampala had fallen by two-thirds, and national HIV prevalence had been cut in half.
  • In Thailand the annual incidence of HIV has declined from 143,000 in 1991 to 19,000 in 2003 through the country’s innovative 100% condom program, which promoted the use of condoms in brothels. The government also promoted public education about HIV and fair treatment of those infected with the virus. Had Thailand not brought comprehensive HIV prevention to scale, it would now have 7.7 million HIV infections, rather than the estimated 580,000 residents currently living with HIV.
  • In Senegal, early investment in awareness-raising, condom promotion, intensive prevention services for populations at greatest risk, and engagement of community leaders and faith-based organizations, combined with high rates of medical male circumcision, succeeded in keeping national HIV prevalence below 1 percent, when neighboring countries experienced significant increases in infections. (Working Group, 2008)

Together, these examples suggest that countries in a wide variety of settings have contributed to changes in HIV risk behaviors and, in doing so, have saved countless lives by averting HIV transmission. Based on the totality of epidemiologic evidence, it appears that national implementation of evidence-informed combination HIV prevention efforts in the 1990s was associated with a 50% to 90% decline in HIV incidence and prevalence in key populations (Working Group, 2008).