Cytotoxic T Cells are designed by our bodies to naturally destroy cancer cells and other damaged cells by checking chemical flags within the body, it can then be ascertained that where cancers and aids are not destroyed the "Flag Recognition System" employed by the Cytotoxic T Cells is either not working correctly or is being fooled by more advanced cancers or diseases!
Knowing that we can use a virus as the delivery mechanisim for cures into cells of the body it may be possible to also use them to "CHANGE THE FLAG" on cancer cells and the aids virus to allow Cytotoxic T Cells to recognise the damaged cells as invaders!
It may be possible that the flag we need to use when the virus infects "Every Cell In The Body" is keyed to deliver another protien to combine with the specific "Protiens" within cancer cells and aids cells (Have to check it is specific with the cancer protein or disease), by doing so the "Flag" is changed an presented on the MHC1 complex for the Cytotoxic T Cell recognition process to be engaged!
It also occurs to me that if a person becomes sick with an unknown virus that Cytotoxic T Cell could be harvested from the body injected into a virus solution containing all the proteins that Cytotoxic T Cells need to duplicate, then the process would be that the Cytotoxic T Cells "Learn" what the virus is and then destroys it!
The Cytotoxic T Cell with the new memory is then injected into the host body from which it was initially harvested and is able to eradicate the virus thus no need for Penicillin's or Antibiotics to even be used!
In Addition the Cytotoxic T Cells from a newborn could be introduced to all viruses and parasites to teach the Cytotoxic T Cells to recognise the virus, if then injected back into the host then that person is then "Immunised" against every known virus and some if not all parasites!
Obviously Testing must be done "Thouroughly before using it on humans, since some viruses may mimic the human system hense the Cytotoxic T Cells might attack the human instead!