Antibody responses in sera as measured by ELISA
and binding of purified IgGs. (A) Rabbits were immunized
with purified CDC/NII MAL VAC-1 by using different adjuvant
formulations at weeks 0, 3, 6, and 9 as indicated by arrows. Antibody
responses to CDC/NII MAL VAC-1 in the sera from rabbits receiving
Freund’s (⋄), copolymer (■), and alum (○) were
measured. Titers were determined based on the highest dilution of the
samples that generated an OD greater than cutoff value (mean ± 3 SD of
preimmunization sera). ODs lower than cutoff value at 1:50 dilution
were considered negative responses. (B) Purified antibodies
at concentration of 50 μg/ml were presented at 5 μl/min to a
Biacore sensor cell loaded with CDC/NII MAL VAC-1 protein.
Inset shows initial velocities of association (450–500
sec).