Ascertainment of the antitetanic immune state in a group of 126 children, 5 to 7 years old, from the infant population of S. Paulo city (Brazil), disclosed 41% and 21% of 5 and 6-year-old individuals respectively, susceptible to tetanus. All the 7-year-old children showed protection against tetanus, revealing a circulating antitoxin content at levels superior to 0.01 IU/ml. By analysis of the results it became clear that susceptibility varies in inverse ratio to age. The mean content of tetanus antitoxin oscillated between 0.0289 and 0.1143 IU/ml of serum.
Tetanus; Tetanus; Tetanus antitoxin; Immunity
