An attorney for the plaintiffs, two women and a man, said the lawsuits filed Monday in Suffolk County are the first filed in Massachusetts against the New England Compounding Center of Framingham.
Chicago attorney Elizabeth Kaveny said the suits are just the "tip of the iceberg" for the company, which has ceased operations and recalled all its medicines.
A company spokesman declined comment.
The outbreak has sickened nearly 300 people, including 23 who died. Each received a steroid shot, mostly for back pain.
Federal health officials matched the shots produced by the New England Compounding Center to the outbreak after finding the deadly fungus in more than 50 unopened vials there.