In development since 2001, the HIVBr18 DNA vaccine developed at the Medical School at the University of Sao Paulo (USP) in Brazil may prevent transmission of human immunodeficiency virus (HIV) and development of acquired immune deficiency syndrome (AIDS). The DNA Vaccine encodes 18 conserved multiple HLA-DR-binding HIV-1 CD4 epitopes capable of eliciting broad CD4(+) T cell responses in multiple HLA Class II transgenic mice. The team of scientists at USP started conducting mouse studies in 2006. Because rodents are not naturally susceptible to HIV/AIDS, the scientists developed their own method – a smallpox family virus containing HIV antigens. The researchers infected the mice with the modified virus and administered the DNA vaccine. The results were a reduction of infection that was fifty times greater than the control group. The next step for researchers is to carry out studies of the vaccine on non-human primates. Specifically, the USP scientists will have access to a colony of 24 rhesus monkeys being provided to them by the country’s Butantan Biomedical Research Institute. Rhesus monkeys are a good natural animal model for the study of HIV because their immune systems are quite similar to that of humans. They are also susceptible to simian immunodeficiency virus which is suspected to be a precursor to HIV. The study will take approximately two years to complete. “Our goal is to test various immunization methods to select the one capable of inducing a stronger immunological response and thus be able to test it on humans,” lead investigator Edecio Cunha Neto told reporters. While the researchers do not expect that their vaccine will entirely cure HIV, there is good preclinical evidence to suggest that human-to-human transmission and the development of AIDS could be prevented. If successful in the upcoming trial, this DNA vaccine could provide a sustainable state of maintenance to infected individuals and prevent infection in others. The University is currently seeking funding from the private sector to proceed with human clinical trials sometime in the next three years.