Based on his findings, I think that it's possible that something like this might be going on:
- A bunch of cells are get infected with HHV6 (or other virus).
- The cells start releasing some sort of substance(s) into the bloodstream which act as a SOS signal.
- The released substance is an immune modulator (undiscovered?) that puts the body into sickness / recovery mode. Namely, it activates the immune system and reduces the energy output of other cells, this way the body is forced to rest, making recovery quicker.
- This process is supposed to stop once the infected cells are healed.
- If however the initially infected cells do not stop releasing that substance, then the process goes on indefinitely and you have ME/CFS. This might be because: (1) the infected cells cannot clear the infection or (2) the infection is cleared, but the cells don't realize that and keep releasing the substance anyway.