Figure 1. The immunization with NE + rF-ptn resulted in serum and BAL antibody responses. Mice were immunized at weeks 0 and 4 and bled on weeks 2, 4 (pre-boost), and 6. Mice were treated with PBS alone, rF-ptn alone or rF-ptn and NE adjuvant. The rF-ptn dose was 4.45 μg/animal at time 0 and 10 μg/animal at week 4. Serum samples were 10-fold diluted and assessed against F protein using ELISA to obtain endpoint titers (A). Mice were immunized with NE + rF-ptn (2.5 µg rF-ptn) or NE + RSV (1.3 × 10⁵ pfu) at weeks 0 and 4. Mice immunized with NE + rF-ptn yielded at least two orders of magnitude higher F-protein specific IgG response as compared with NE + RSV immunized mice (B). Mice immunized with NE + rF-ptn yielded on average two orders of magnitude higher IgG RSV specific response as compared with NE + RSV immunized group of animals (C). Mice vaccinated with NE + F yielding increased levels of IgA (D). Line indicates geometric mean titer. (*P < 0.05, **P < 0.01, ***P < 0.001).