And there is another grey area.
Organisms like rickettsia are more sophisticated than viruses, yet–like viruses–they require a living cell to invade and grind out copies of themselves, but they still have cell walls and are susceptible to antibiotics.
So they are almost like an over-simplified bacteria, and they cause diseases like typhus and Rocky Mountain spotted fever (along with several others).
There are many grey areas in nature, and definitions are not always exact and precise.