It hasn’t been conclusively shown yet, but Pepper Mild Mottle Virus (PMMoV) lives in humans and may cause an immune response. Researchers are studying it now. It’s presence is also a major indicator of human fecal contamination in groundwater because it survives for so long in our gut.

Some sources:

Humans Have Antibodies against a Plant Virus: Evidence from Tobacco Mosaic Virus

Pepper Mild Mottle Virus, a Plant Virus Associated with Specific Immune Responses, Fever, Abdominal Pains, and Pruritus in Humans