Serum levels of antibody to toxoid during tetanus and after specific immunization of patients with tetanus.

Levels of serum antibody to toxoid in patients with tetanus who were immunized with toxoid differed from those in immunized healthy persons in two respects. (1) Base-line levels preceding immunization were higher among patients with tetanus than among young or elderly healthy person, even though the patients with tetanus were evaluated before specific serotherapy. This observation suggests the occurrence of immunostimulation, whether specific or not, by disease during the incubation period. (2) No significant increase in levels of antibody to toxoid was detected among patients with tetanus from the first to the last evaluable serum sample, whereas a significant increase was observed among healthy persons. Specific immunosuppression induced by tetanus toxoid or serotherapy could account for this ineffectiveness of immunization among patients with tetanus, although nonspecific immunosuppression induced by prolonged and severe illness cannot be excluded. Among healthy persons, active immunization is less effective in elderly persons than in young persons [2]. However, age cannot, by itself, account for the type of antibody production observed in patients with tetanus.