Total C. pneumoniae IgG antibody levels measured by the MIF and EIA methods and levels of mouse Hsp60 IgG antibodies measured by EIA. The study group, the number of inoculations given (e.g., six inoculations [6x]), and the age at which the first inoculation was given (e.g., 8 weeks) are indicated. Cpn, C. pneumoniae; chol., cholesterol; w, weeks; Geom., geometric.