The Antitoxin Response of Partially Immunized Guinea Pigs to Infection with Tetanus Spores

Summary Guinea pigs given a single injection of 1 ml. of tetanal toxoid will react subsequently with an increased antitoxin titer when infected with a lethal dose of spores. This rise in titer will first be evident on the seventh day after infection in some of the guinea pigs, especially in those that are without symptoms or if with symptoms, in those that will recover. This rise is small, a significant one not taking place until the 8th to 10th day, in contrast to the significant rise in titer that takes place on the 4th–5th day when similarly prepared animals are given toxin instead of spores. There is no evidence that the increase in titer thus induced influences the clinical course. It is also shown that when an additional dose of toxoid is injected simultaneously with the spores, a significant rise in titer is evident on the 5th day.