FIG. 2.
Antitoxin antibody responses in vaginal fluids after two vaginal doses of recombinant CTB in women using different types of contraceptive methods. The numbers of responders are given below the x axes. Responders were defined as having a >2-fold increase in the ratio of the CTB-specific antibody titer to the total-immunoglobulin concentration between pre- and postvaccination specimens. Specimens from one volunteer in the OCP group contained too low IgA and IgG concentrations (≤40 μg ml−1) and were therefore excluded from further analyses.