2007-11-18-世界卫生组织-WHO_Informal_Consultation_of_the_Minimum_Potency_Specification_for_yellow_fever_vaccines_16页_130kb

WHO Informal Consultation on Minimum Potency Specification for Yellow Fever Vaccines

Key Objectives and Outcomes

The consultation aimed to review current potency data, address variability in measurements, and propose switching to International Units (IU) for consistency. Current specifications vary due to Laboratory-to-laboratory differences in LD50 measurements.

Conclusions

• The minimum potency specification should be expressed in IU instead of LD50 to reduce variability.
• All existing vaccines are considered satisfactory based on clinical use; no changes are needed without clinical justification.
• For new products, specifications should be set through clinical trials and expressed as ≥ 3.0 log IU per dose.

Recommendations

• Use IU for potency expression in all vaccines.
• Changes to existing specifications must be supported by clinical data.
• Production transfers should include IU specifications.
• WHO should provide guidance on calibrating standards against the International Standard to support IU implementation.

Follow-Up Actions

The proposal will be submitted to the WHO Expert Committee on Biological Standardization in October 2008 for formal consideration and further development.