Novel Image-Based Titration Method for Potency Testing of Diphtheria Toxoid in a Vero Cell Assay.

Area of Science:

• Immunology
• Vaccinology
• Cell Biology

Background:

• Diphtheria toxoid potency is traditionally assessed using the Vero cell assay, relying on cell metabolism or morphology.
• Current methods are time-consuming and subjective, posing challenges for efficient vaccine quality control.

Purpose of the Study:

• To develop and validate a novel, objective, and convenient method for determining diphtheria toxoid potency using cell image analysis.
• To compare the efficacy of cell image analysis with existing methods for potency determination.

Main Methods:

• Developed a cell image analysis technique for endpoint determination in the Vero cell assay.
• Assessed the feasibility and accuracy of image analysis by comparing it with microscopic observation and cell metabolism measurements.
• Evaluated the method's performance on commercial diphtheria vaccines.

Main Results:

• Cell image analysis demonstrated effectiveness as an endpoint determination method.
• Potency values obtained through image analysis were comparable to those from traditional cell metabolism and microscopic observation methods.
• The image analysis method proved to be objective and convenient.

Conclusions:

• Cell image analysis is a reliable alternative for diphtheria vaccine potency testing.
• This novel method enhances objectivity and convenience in vaccine quality control processes.
• The findings support the adoption of image analysis for routine diphtheria toxoid potency determination.