FIG. 1.

Serum antibody response to B/Panama PSA. Mice were immunized three times with B/Panama, and serum samples were obtained after each immunization as detailed in the text. (a) Anti-B/Panama IgG ELISA. The columns represent the GMT, and the error bars represent the standard errors of the mean (SEM). (b) Anti-B/Panama HAI. Columns represent the mean log₁₀ HAI, and the error bars show the SEM; numbers above error bars show the number of sera giving a positive response per number of sera tested. (c) NAI. NAI was assayed on pooled post-third-dose sera diluted 1/75. The means of the different groups at the equivalent time points were compared to determine if they were significantly different (P < 0.05). #, mean significantly greater than that of the PSA i.n. group; ∗, mean significantly greater than that of the PSA + gellan group. Abbreviations: I/N, intranasally administered; S/C, subcutaneously administered.