FIG. 2.

The activity of the nHgbA_I/MPL antisera is lower than that of the antisera from nHgbA_I/Freund's-immunized animals. Sera were collected preimmunization (prebleed), before the second immunization, and prior to challenge infection (three weeks after the third immunization). Data are expressed as OD₄₀₅ readings and given as median ± variance. Solid lines represent data from each pig immunized with nHgbA_I/Freund's adjuvant (1F, 4F, 5F, and 6F) (1), whereas dotted lines represent data from pigs immunized with nHgbA_I/MPL adjuvant (3M, 4M, 7M, and 8M). ELISA data for week 6 (prior to 3rd immunization) are not shown due to an incomplete data set for nHgbA_I/Freund's antiserum samples. P values comparing anti-nHgbA_I antibodies using Freund's and MPL adjuvants after one and after three immunizations (just prior to challenge) were 0.029 and 0.057, respectively, and were determined using the Mann-Whitney rank sum test (n = 3).