Poisoning by smallpox vaccine

This code signifies an adverse reaction or toxic effect resulting from the administration of a smallpox vaccine. It encompasses systemic or localized symptoms arising directly from the vaccine itself, rather than from an allergic response or improper administration technique.

Use this code when documentation clearly states "poisoning by smallpox vaccine" or describes symptoms directly attributable to the toxic effects of the smallpox vaccine. This typically applies to historical cases given the eradication of smallpox and discontinuation of routine vaccination. Documentation should specify the vaccine as the causative agent of the adverse effect.

• Differentiate from allergic reactions (e.g., urticaria, anaphylaxis) to the vaccine, which would be coded differently.
• Ensure the documentation specifies "poisoning" or a toxic effect, not just a general adverse effect or complication.
• This code is largely historical; its use in current practice is extremely rare.