FIG. 8.

Immune responses to an influenza virus NP peptide following EPI. Mice were immunized by either EPI or i.p. injection with 5 μg of the A/PR8 NP peptide on days 0 and 28. Control mice were vaccinated with 2.5 μg of DNA plasmid encoding a full-length NP. (A) CTL responses were determined on days 37 and 39. Each data point represents CTL activities in pooled splenocytes (n = 4). (B) Postboost antibody responses were determined by an ELISA using inactivated A/PR8 as the detection antigen. Data are individual serum IgG titers; solid lines indicate mean titers.