An anonymous reader writes: Immunologists have developed a synthetic molecule that's able to attach to HIV and prevent it from interacting with healthy cells. "HIV infects white blood cells by sequentially attaching to two receptors on their surfaces. First, HIV's own surface protein, gp120, docks on the cell's CD4 receptor. This attachment twists gp120 such that it exposes a region on the virus that can attach to the second cellular receptor, CCR5. The new construct combines a piece of CD4 with a smidgen of CCR5 and attaches both receptors to a piece of an antibody. In essence, the AIDS virus locks onto the construct, dubbed eCD4-Ig, as though it were attaching to a cell and thus is neutralized." The new compound was tested in monkeys. After successively higher injections of HIV, all four monkeys who received the compound beforehand stayed from free infection. Any potential medical treatment is still a ways off — the researchers plan more trials in monkeys before involving humans in the testing.