[Iv]

I don't think this is relevant in that case. I am not an epidemiologist but I worked with people who were studying HIV. My understanding is that while the HIV mutates fast, it does not create new strains during the treatments.

A given strain can have some variability but will share general traits.

HIV strains are named and numbered: https://en.wikipedia.org/wiki/Subtypes_of_HIV

An efficient treatment against a specific strain would save millions of lives. An efficient treatment against the 99% of them that are the most prevalent would basically solve the epidemics.

The problem is that people often end up with more than one strain. This is why doctors tell HIV+ people to continue protect themselves and were worried about the appearance of "free-sex parties" for HIV+ individuals. Most people do not differentiate between strains but if you got HIV from a partner, you may have had only a part of their strains, you should not have unprotected sex if you want to maximize your chances.