Table 1.

Comparison of Antibody Responses to Tetanus and Diphtheria According to Sex^a

Study Population	DT Ab Titer, Mean (SD) IU/mL	DT Ab Half-life (95% CI), y	TT Ab Titer, Mean (SD), IU/mL	TT Ab Half-life (95% CI), y
All	0.35 (0.6)	27 (18–51)	3.6 (4.6)	14 (11–17)
Men	0.31 (0.39)	21 (14–46)	3.89 (5.24)	14 (11–19)
Women	0.37 (0.68)	42 (20–∞)	3.46 (4.26)	13 (10–18)

Abbreviations: Ab, antibody; CI, confidence interval; DT, diphtheria toxin; SD, standard deviation; TT, tetanus toxin.

^a Antibody titers to DT or TT were determined from 546 subjects (187 men and 359 women). Antibody half-life estimations (in years) were based on 392 subjects from whom data was available (134 men and 258 women).