CD8A and AIDS: Weproposed that if CD8 T cell pressure is ‘relaxed’ due to HIV-inducedimmunodeficiency this might facilitate reversion of costly escape mutations, leadingto a restoration of viral fitness and the subsequent rise in viraemia seen in AIDS.Reversion of costly drug resistance mutations has been associated with a rise inviral load and clinical progression [26], and therefore a precedent exists to potentially explainthe rise in viral load associated with the onset of AIDS.