ABSTRACT
A study concerning changes in anti-tetanus antibody (ATA) levels in 50 patients with tetanus following the injection of antitetanic serum of equine origin and of toxoid, the first dose of the latter being given 24 hours after the administration of serum and the others at intervals of 5 to 7, 15 and 30 days. Repeated estimation of ATA demonstrated, regardless of the toxoid dose protocol adopted, that levels did not reach 0.1 IU/ml on the 30th day and that they only rose late. By contrast, after a booster, the increase was the same as that seen in subjects who had not acquired tetanus. The various factors which may underly defective active immunisation during the acute phase of tetanus are discussed. Heterologue serum therapy, which has been held responsible, cannot be considered to be a responsible factor since patients who did not receive serum behaved in exactly the same way as those who had. By virtue of this "gap" in the acquisition of immunity, the use of heterologue serum is recommended to neutralise any remaining circulating toxin as rapidly as possible.
