What Type of Impact Would an AIDS Vaccine Have on Brazil?

Catherine Auten

Photo by gaby_bra

AIDS has claimed 162,545 Brazilian lives between 1985 and 2007 (Stover, 3). These staggering numbers cause Brazil to be a place with a “concentrated epidemic” of AIDS. Because there exists such a concentrated number of people infected with AIDS in Brazil, scientists found this country to be the perfect subject for showing just how large of an impact a vaccine for HIV could have on the country. The scientists’ study predicts the influence of a potential HIV vaccine and the study appears to be quite complete; they predicted the impact of a vaccine on low-risk, medium-risk and high-risk individuals. They also predicted the impact of vaccines with different levels of efficacy. This study can offer information for how helpful a vaccine could potentially be for, not only, Brazil, but the rest of the world.


Because a large number of Brazilians are already infected, the government is highly committed to treating AIDS in the country. So, the study was conducted under the assumption that those who would be receiving the vaccine would also be receiving antiretroviral (ARV) treatment provided by the government (Stover, 1). They also assumed that a positive test result for HIV would not be a requisite for receiving the vaccination (Stover, 2). Given this information, the study shows results for a vaccine introduced in 2015 with 80% coverage achieved by 2020. The study offers the result of the vaccine in 2050 (Stover, 2-3).

The results found that a vaccine with only 40% effectiveness could reduce the number of HIV infections by 73% in the general population (Stover, 3). In medium or high risk individuals, i.e. men who have sex with other men or intravenous drug users, vaccinations could result in a 52% reduction in infections. (Stover, 3) This suggests that the vaccine is most beneficial when given to people who are likely to be exposed to the virus and likely to spread the virus to others. The report on the study specifically pointed out that the smallest impact would occur when the vaccine was given to only adolescents (Stover, 3). When using a 70% effective vaccine, the study showed that the number of new infections could be reduced by 92% (Stover, 3). With the 70% effective vaccine a 74% reduction in new infections could be seen when only vaccinating medium and high risk individuals (Stover, 3).

The study also address the possibility that those with the vaccine may behave with less inhibition because they feel protected (Stover, 5). For example, with the vaccine which offers a 40% efficacy rate, when condom use is gradually reduced, the reduction in infections is only 42% instead of the projected 73% when the “disinihibition” was not calculated (Stover, 5). This means that for a vaccine to have an optimal impact, individuals who receive the vaccine should still be educated on safe sex. Furthermore, it is imperative that medium and high risk individuals be vaccinated as well as low-risk and adolescent individuals. This ensures that the greatest impact can occur from use of the vaccine. However, even with these caveats, it is clear that investing in vaccination research will be well worth the cost, at least for Brazil.


Works Cited

John Stover, et al. "Modeling HIV Vaccines In Brazil: Assessing The Impact Of A Future HIV Vaccine On Reducing New Infections, Mortality And Number Of People Receiving ARV." Plos ONE 5.7 (2010): 1-10. Academic Search Complete. Web. 12 Feb. 2012.