‘In recent years, many men of science have come to realize that the scientific picture of the world is a partial one.’ –Aldous Huxley
Despite 28 years of research, there is still no vaccine that provides effective protection against HIV, and in that time around 25 million people have died of HIV-related causes. To understand why creating a vaccine is so hard, you need to understand HIV. This is no ordinary virus. […] The virus is the most diverse we know of. It mutates so rapidly that people might carry millions of different versions of it, just months after becoming infected. HIV’s constantly changing form makes it unlike any viral foe we have tried to thwart with a vaccine. […]
Vaccines train the immune system to recognise part of a virus, creating a long-term armada of antibodies that seek and destroy the invader, should it ever show its face. For HIV, the most obvious target is gp120, the surface protein that it uses to attach itself to human cells. But gp120 also constantly changes shape, making it difficult to recognise. It also comes in clusters of three that are shielded by bulky sugar molecules, hiding it from the immune system.
On top of that, HIV targets immune cells, the very agents that are meant to kill it. And it can hide for years by shoving its DNA into that of its host, creating a long-term reservoir of potential infection.
So, creating an HIV vaccine is like trying to fire a gun at millions of shielded, moving targets. Oh, and they can eat your bullets.
photo { Nan Goldin }
