FIG. 6.

Detection of capsule-specific IgM antibodies with ELISA. Mice were vaccinated with capsule II strain D39ChiplicB31 and sera were collected at day 10 postinfection. Sera of eight mice that received the vaccination were compared to control sera of three naive mice for the production of IgM antibodies specific to pneumococcal capsular polysaccharide II (A) or pneumococcal capsular polysaccharide III (B). The scatter plots show results for individual animals and the means of the whole test group as well. We found significant (P < 0.05) production of antibodies that specifically recognized polysaccharide capsule II.