Valve body and fluid injector

A valve body (5) for a fluid injector (1) having a central longitudinal axis (L) and comprising a base body (10) is specified. The base body (10) has a side wall (130) defining a recess (132) extending from a fluid inlet side (12) to a fluid outlet side (11) of the base body (10). The side wall (130) has a thin portion (102), the thin portion (102) having a decreased wall thickness (102) relative to further portions of the side wall (130), which adjoin the thin portion (102) in longitudinal direction (L) towards the fluid inlet side (12) and the fluid outlet side (11), respectively. The valve body (5) comprises a reinforcement jacket (320) which is rigidly coupled to the base body (10) and axially overlaps the thin portion (102) having the decreased wall thickness.