Conventional Test Method:

Lethal/paralytic challenge test in the batch potency testing of tetanus toxoid vaccines for human use (Methods A and B in PhEur 2.7.8)

Alternative Test Method:

Name & Description:

Toxin Binding Inhibition (ToBI) Test for Batch Potency Testing of Tetanus Vaccines

The ToBI test estimates in vitro the quantity of tetanus antibodies in serum of immunized guinea pigs. Serial dilutions of the test serum and a standard serum are pre-incubated with a fixed concentration of tetanus toxin. Serum-toxin mixtures are transferred to an equine anti-tetanus IgG coated microtiter plate. Peroxidase-conjugated equine anti-teatanus IgG is added and tetanus antibodies are visualized by adding substrate. Antibody titre is estimated by comparing the dose-response curves of the test and standard serum.

Validation Status:

EU: Endorsed as valid by ECVAM (2000)

Regulatory Status:

EU: Accepted into PhEur (Method C, 2.7.8) (2003)

US: 21 CFR 610.10

Effect or Potential Effect on Animal Use:

Reduction
(Single-dilution test instead of multi-dilution)

Refinement
(Does not rely on death as an endpoint)

References:
Information Last Reviewed:
May 2012