I don't know where you're getting this information from, AIDS isn't an autoimmune disorder. HIV destroys immune cells directly. The symptoms are mainly from secondary infections. Also, if your immune system realizes that your own cells are making virus particles, it will destroy them... and every other cell will survive. That's what happens when you catch a cold - every virus works that way. mRNA is even better because it probably won't cause any of your cells to get targeted for destruction. The failure mechanism you're proposing would at worst make it as bad as some other vaccines.