I suppose in a future world, you possibly could create a respiratory virus that causes a cell to create two viruses, one copy of the original, and one copy of standard HIV.
There's a lot of issues though: For one the viral envelope would have to actually fit all that genetic material inside it. For two, it's not like copying a file... The viral genome has instructions for making more of itself, and that includes a hideous protein folding and packaging problem that is really non-trivial. I don't think you could take two off the shelf viruses and just splice them together and stuff them in a virus, it would just at best create a virus that after the first generation, just created two viruses. Finally, even if you did do this, the respiratory part of the virus derives zero benefit from the HIV component, so it will, after a few generations probably just ditch that part and evolve back into a cold virus.
I suppose in a future world, you possibly could create a respiratory virus that causes a cell to create two viruses, one copy of the original, and one copy of standard HIV.
There's a lot of issues though: For one the viral envelope would have to actually fit all that genetic material inside it. For two, it's not like copying a file... The viral genome has instructions for making more of itself, and that includes a hideous protein folding and packaging problem that is really non-trivial. I don't think you could take two off the shelf viruses and just splice them together and stuff them in a virus, it would just at best create a virus that after the first generation, just created two viruses. Finally, even if you did do this, the respiratory part of the virus derives zero benefit from the HIV component, so it will, after a few generations probably just ditch that part and evolve back into a cold virus.