Statement on the application of the ELISA procedure for batch potency testing of tetanus vaccines for human use.

The results obtained with the ELISA procedure in the international validation study on alternative methods for batch potency testing of tetanus toxoid vaccines for human use were reproducible, both within and among the participating laboratories that performed the tests. The ELISA procedure proved applicable to testing a diverse group of tetanus toxoid vaccines for human use, of different potencies, composition and combinations. The concordances between the potencies derived from the in vitro serological (ELISA) data and from the in vivo data were very good. The ELISA was able to distinguish between highly potent and less potent vaccines. The Committee therefore agrees with the conclusion from this formal validation study that the ELISA procedure is scientifically validated for use as a replacement for the challenge procedure in the batch potency testing of tetanus toxoid vaccines for human use, and that it is ready to be considered for regulatory acceptance.