In humans, HIV specifically targets CD4 cells, which are essential to immune surveillance. HIV uses an enzyme called reverse transcriptase to convert the CD4 cell into what amounts to an “HIV factory.” Once the cell becomes completely filled with HIV particles, it bursts, which both destroys the cell and allows the virus to circulate and infect other CD4 cells. Eventually, as CD4 lines become depleted and fall to a value less then 200, the individual develops AIDS, marked by lethal opportunistic infections.
Highly-active antiretroviral therapy (HAART) targets HIV from various approaches, most of which stop the virus from attaching to CD4 cells or from replicating once inside. Because HIV is easily susceptible to mutation, finding a vaccination has been very difficult; all vaccine trials thus far have failed. Once an individual becomes infected with HIV, their immune system develops antibodies which are ineffective at killing HIV. HIV tests react to the presence of these antibodies, which is diagnostic for HIV infection.
By developing antibodies which are effective at destroying the virus, scientists would essentially have a cure. But these data shouldn’t be interpreted as a sign of an immediate end to the pandemic. An AIDS vaccine isn’t “in the wings.” Years of work may lie ahead before a product is ready for human use. Nevertheless, the work is a ray of hope for a future. Let’s hope all the new medical discoveries indicate HIV’s days are numbered. Congratulations to this team of scientists!