Antibody response in transgenic rats immunised with tau peptide vaccine determined by enzyme-linked immunosorbent assay. Tau peptide vaccine induces high antibody levels specific to the tau peptide 294KDNIKHVPGGGS305. No antibody response was observed in the mice immunised with adjuvant only. Data shown are serial twofold dilutions of animal sera (A). Antibodies elicited by vaccination exhibited statistically significantly higher binding activity to tau peptide and to mis-disordered tau (151-391/4R) than to full-length tau 2N4R (***P = 0.0003 and **P = 0.0028, respectively) (B). EC50, Half-maximal effective concentration. Vaccine-induced antibodies specific to mis-disordered tau are prevalently of the immunoglobulin G (IgG) isotype (C). The data shown are means with error bars representing SD.