FIG 5.

DB1 immunogenicity in cotton rats. Groups of 6 cotton rats were infected i.n. with either RSVA/Tracy, DB1, or a control. Serum titers of neutralizing antibody against RSVA/Tracy (A) and RSVB/18537 (B) were measured at the indicated days postinfection by a microneutralization assay. Serum obtained on day 46 p.i. was then pooled and analyzed by IgG ELISA to RSV-A2 (C). Total IgG titers are represented as means + SDs of three pooled replicates. Total IgA titers of individual nasal wash specimens collected on day 46 p.i. were also analyzed by IgA ELISA to RSV-A2 (D). Data represent means + SDs. *, P < 0.05; **, P < 0.005; ***, P < 0.0005 by two-way ANOVA with Tukey multiple-comparison test (A and B) or two-tailed Student's t test (C and D). NS, not significant.