After 40 years of AIDS research, where is the vaccine?

The short, and rather self-evident, answer is that there isn’t one. But you already knew that.

The reason, which is perhaps what you’re really asking, is that HIV behaves in a different way to other viruses. Most other viruses, you can essentially train the immune system to know how to fight back when the invader arrives. HIV, on the other hand, actually attacks the immune system, which makes training it much harder.

HIV has to evolve to survive because it cannot operate without the hosts machinery.

HIV has to circumvent the body’s immune response, and develop mechanisms to evade the medications used to treat them.

the principle of Darwinism is apt in this discussion. Survival of the fittiest is the motto.

HIV infection is impossible to reverse.

Given the two types of HIV and the multiple variants, there are many opportunities for this virus to mutate.

A vaccine may provide protection against one strain or a few strains, but not all of them.

we’re a long ways away from a vaccine. There are ethical considerations, and financial considerations to an RCT.