There was a brief piece about the beginning of the HIV virus on BBC4 tonight, (about past Horizon programmes). The science was most interesting. The virus actually becomes a part of the cell, and is in every cell, so one cannot attack it without destroying all the cells of the body. And the statistics show that in Africa (where there are many millions of victims) it is mainly heterosexually-transmitted, plus across the placenta to the foetus, and there are statistically not very many homosexually-transmitted cases in that continent. There are (and I've met some) cases of HIV in prisons, from needle-sharing. It seems strict use of condoms for all sexual activity would be the way forward, and education for all those at risk. It would be great if a vaccine could be developed, but it looks unlikely given the ability of the virus to mutate and adapt rapidly.