An ELISA system for tetanus toxoid potency tests: An alternative to lethal challenge

Area of Science:

• Immunology
• Vaccine Potency Testing
• Animal Welfare Science

Background:

• The traditional tetanus toxoid (Ttd) potency test involves challenging immunized animals with tetanus toxin, causing significant animal distress.
• There is a critical need for alternative methods that align with animal welfare principles and reduce suffering.

Purpose of the Study:

• To develop and validate an alternative method for Ttd potency testing using ELISA antibody titers.
• To replace the current animal challenge test with a more humane and ethical approach.

Main Methods:

• Mouse sera from immunized animals were analyzed using ELISA to determine antibody titers.
• Absorbance scores derived from ELISA were used to calculate Ttd potency values and confidence intervals.
• Raw ELISA absorbance data was also explored as an alternative to assigned scores.

Main Results:

• Potency values and confidence intervals calculated using the ELISA absorbance score system were comparable to those obtained from the traditional symptom score system.
• Utilizing raw ELISA absorbance yielded similar results to using assigned absorbance scores, indicating robustness.

Conclusions:

• Enzyme-Linked Immunosorbent Assay (ELISA) offers a viable alternative to the lethal challenge method for Ttd potency testing.
• This ELISA-based approach can be implemented globally, improving animal welfare in vaccine potency assessments.