Anti-CII IgG and IgG2a levels were reduced in protected mice. Serums were taken from 56 days after CII challenge from ESCIA mice, ASCIA mice and CIA mice. The levels of anti-CII IgG was measured in serially diluted serum and the levels of subclasses of anti-CII IgG1 or IgG2a were measured from 1:400 diluted serum by ELISA. (A) anti-CII IgG in ASCIA vs CIA (B) anti-CII IgG in ESCIA vs CIA (C) anti-CII IgG1 (D) anti-CII IgG2a. Results were obtained from 10 to 15 serum samples collected from two or three independently performed experiments. Data presented were the mean OD ± SEM. Asterisks*** and ** represented P < 0.001 and P < 0.01 respectively by two way ANOVA for IgG or by one-way ANOVA for subclasses with Bonferroni multiple comparison test.