According to the New England Journal of Medicine article, those white blood cells are still targeting and killing the B-cells. From my (non-biologist) reading of the article, they crafted a virus which targeted all B-cell, of which, some were lukemia. Apparently there are treatments to restore B-cells in a person, so the article seemed to imply once the T-cell count (the "serial killer" white blood cells) went down, they would treat him to restore his normal B-cell count.

Like you, I'm unclear on what exactly the side-effects are here. If they boost the B-cell count in the patient, do they risk re-introducing lukemia? Are these "serial killer" white blood cells a general immunosupressant? There was a part of the article about a developed resistance in the B-cells that I didn't understand.

Either way pretty amazing, and it sounds like while the patient had the worst flu of his life for five days, it's way better than chemo

According to this article: http://www.geek.com/articles/geek-pick/hiv-virus-used-to-tur...

"More good news stems from the fact that the modified cells remain in the body and have been seen to reactivate and kill new cancer cells as long as 12 months after they were first injected."

Incredible stuff :)

It almost sounds like a cancer vaccine.