Anti-NP immune responses in mice immunized with NP with or without TAK-779 treatment. Two weeks after TAK-779 cessation, total anti-NP IgG antibody titers were detected by ELISA in sera from naïve mice, mice treated with TAK-779 (TAK), mice immunized once (NP) or twice with NP (NP2) and mice immunized once (TN) or twice (TN2) with NP and treated with TAK-779. (A) One NP immunization; (B) two NP immunizations. IgG1 (C) and IgG2a (D) isotyping were carried out for mice from naïve, TAK, NP and TN groups. Sera were diluted 1:10,000.