Kinetics of antigen-specific antibody responses as measured by ELISA in 12 individuals following booster vaccination (week 0) with TT. A boost in the levels of TT-specific serum IgG was evident in all the vaccinated subjects, with a maximum at the indicated week, but no significant changes were detected in either PPD- or C albicans–specific antibody responses. Data for each time point represent the mean value of at least 4 replicate wells. SD bars are not shown for clarity. Positive symbols indicate different degrees of positive responses analyzed at the week of maximal TT response (indicated) compared with the prevaccine (week 0) response and were given according to the criteria stated in “Proliferative responses.”