Human Immunodeficiency Virus and AIDS

Human immunodeficiency virus (HIV-1 and HIV-2) are enveloped retroviruses belonging to the Lentivirus genus in the family Retroviridae. HIV-1 was identified in 1983 and by 1984 shown to be the causative agent of acquired immunodeficiency syndrome (AIDS) in humans characterized by a progressive depletion of CD4-positive T-lymphocytes, cells necessary for an intact immune system. HIV-2, which causes a less severe disease than HIV-1, was isolated from AIDS patients in West Africa in the region from Guinea-Bissau and Cape Verde in 1986. While HIV-1 is thought to have been derived from SIV infected chimpanzees (Pan troglodytes troglodytes), it is believed that HIV-2 resulted from zoonotic transmission from SIV infect sooty mangabey (Cercocebus atys).

AIDS was first recognized in the United States in 1981 with the unexplained occurrence of Pneumocyuctis carinii pneumonia and Kaposi’s sarcoma in previously healthy homosexual men from New York and San Francisco. Since then, infection by HIV has taken on worldwide proportions. As of December 2000, 36.1 million people were living with HIV/AIDS. Three million people died of HIV/AIDS in 2000 and since the epidemic began, the overall cumulative death toll is estimated to be 21.8 million.

To combat this devastating disease, nucleoside analog reverse transcriptase inhibitors were first introduced in 1987 and the protease inhibitors in 1995. Although these drugs when used in combination, so called “triple therapy” or “highly active antiretroviral therapy (HAART),” are very effective against HIV and AIDS, the treatment is not curative, there are side effects, and drug resistant HIV strains can develop. In addition, some infected populations have limited access to the drug regimen with one of the causative factors being the cost of therapy. Thus, it is imperative to develop an effective vaccine against HIV to combat the AIDS pandemic. BMI is developing an AIDS vaccine and applying its Immune Dampening and Refocusing Technology to the outer HIV envelope glycoprotein gp120/gp41, which is the main mediator of viral fusion and entry with host receptors CD4 and chemokine receptors CCR5 and/or CXCR4.