FIG. 2.

Serum IgM-IgG before and after booster given at day 21. Mean antibody titers are given as −log₂ (dilution × 10) ± standard deviation (error bars) (n = 6). Mice were given antigen-conjugated microparticles orally (⧫), microparticles plus free antigen orally (▪), free antigen orally (•), or antigen-conjugated microparticles intramuscularly (▴). Naive mice were used as a control (×). The group that received antigen-conjugated microparticles orally had significantly higher antibody titers over time compared to both the groups that received the free antigens orally (P < 0.05). The open symbols represent the anti-LPS titers from pooled sera at days 28 and 35.