Shouldn't this be more of a temporary problem? As soon as there is a vaccine its patents will expire at least 20 years afterwards. And then lots of much cheaper vaccines will flood the market.
I think his point is that much of the problem of preventing the spread of HIV has less to do with the science of killing the virus, and more to do with the difficulty of actually getting it in the hands of people who need it. There are already very cheap, readily-available ways of preventing HIV transmission (condom use comes to mind), but people aren't using those. The reasons are varied, but some cite misinformation, cultural misconceptions, government ineptitude, and so on. Even if there were a 99% effective HIV vaccine that were as cheap as water, it still wouldn't make it into the hands of every person in the developing world. Proof of that is the fact that we can't even get water to all of these people.