Simmons becomes infected with an alien virus after exposing herself to a group of people that have come into contact with a Chitauri helmet.
Did You Know?
When Simmons shows Coulson the "brain cells", they clearly lack axons/dendrites, which are branchings from the cell walls that make neurons easily identifiable. Brain cells normally use these branches to produce tiny electrical impulses. The cells shown look like red blood cells. See more
That her medical report?
Mine, actually. Blood work finally came back. I'm perfectly normal - little heavy on the iron. But don't worry - you don't have to start calling me Iron Man.
Wasn't planning on it.
References The Avengers
Agents of S.H.I.E.L.D. Theme Song
Written by Bear McCreary See more