Figure 1 Detection of S1-specific IgG and IgA antibodies in serum and BALF.
Mice were immunized twice by intratracheal (IT) administration of S1 combined with or without SF-10 at days 0 and 14. Another group of mice were immunized by intramuscular (IM) injection of S1 at the same time schedules. At two weeks after the last immunization, the levels of S1-specific IgG in serum (A) and S-IgA in BALF (B) were measured by ELISA. Data represent S1-specific antibody titer of individual mice (open rhombus) and their geometric mean (solid squares) (n = 6 mice per group). Differences between same times immunization groups were analyzed by the non-parametric Mann–Whitney U-test.**P <0.01 vs S1-IM,††P <0.01 vs S1-IT.