Underdosing of vaccines and biological substances, sequela

This code signifies a patient's underdosing of a vaccine or other biological substance, leading to a long-term or residual effect. It indicates that the patient did not receive the full or appropriate dose of a biological agent, and this deficiency has resulted in a current health problem. This is a sequela code, meaning it's used to report conditions that are the late effects of the underdosing event.

Use this code when documenting a current medical condition that is a direct consequence of a past, insufficient administration of a vaccine or other biological substance. Examples include a patient presenting with a preventable infectious disease due to an incomplete vaccination series, or an ongoing immune deficiency resulting from inadequate biological therapy. This code is appropriate when the underdosing event itself is no longer acute but its effects are still present.

• Always sequence this code after the code for the specific condition or disease that resulted from the underdosing.
• Ensure documentation clearly links the current condition to a past underdosing event of a vaccine or biological substance.
• Do not use for acute underdosing events; this code is specifically for sequelae (late effects).