My girlfriend has no fever but has severe muscle & joint aches & has thrown up. Does this sound like the flu it maybe poisoning? She had a flu shot.

Viral illness. This does sound like a viral illness. However it is difficult to tell if it is the flu. Persons with the flu usually have a moderate fever. Not likely food poisoning as that does not usually result in muscle and joint aches.
Flu over poisoning. . If u ate the same thing, it would b likely that u would have been sick also. Really sounds like the flu. Since this is viral there is no treatment other than treating the symptoms. Rest, fluids, get a rx 4 Flonase if all stuffed up ; ride it out. Also b on the lookout as u may b next.