Underdosing of oth vaccines and biological substances, init

This code signifies a patient's condition resulting from receiving an insufficient amount of a vaccine or other biological substance, leading to a suboptimal or absent therapeutic effect. This underdosing is the primary reason for the current encounter and may necessitate further intervention.

Apply this code when a patient presents with symptoms or a lack of expected immunity directly attributable to an inadequate dose of a vaccine, antitoxin, or other biological product. This includes situations where a prescribed or recommended dose was not fully administered, or when a patient self-administered an insufficient quantity.

• Always assign an additional code for the specific adverse effect or clinical manifestation of the underdosing.
• Ensure documentation clearly supports that the underdosing is the reason for the encounter and not merely an incidental finding.
• This "initial encounter" seventh character indicates the patient is receiving active treatment for the underdosing.