FIG. 4.

Reactivities of polyclonal sera from BALB/c mice immunized two times i.p. with 20 μg of BBG2Na (A) or three times i.p. (B) or i.n. (C) with RSV-A (10⁵ TCID₅₀) against overlapping 12-mer peptides spanning the region containing residues 130 to 230 of the RSV-A (Long) G protein. Intraperitoneal immunizations were undertaken in 200-μl volumes containing 20% (vol/vol) Alhydrogel. Mice were bled 10 days after the last immunization, and sera were tested in Pepscan analyses. The sera were diluted 1:5,000, 1:5,000, and 1:2,500 for anti-BBG2Na, anti-RSV-A i.p., and anti-RSV-A i.n., respectively. (D and E) Reactivities of two RSV-convalescent-phase human sera diluted 1:5,000. N-terminal residues of every third peptide are indicated on the x axis. Reactivity peaks are numbered to facilitate direct comparison of the various sera; the numbers correspond to the first amino acid residues of the implicated peptides. The conserved cysteine domains are indicated by horizontal bars. OD, optical density.