Fig. 1 | npj Vaccines

Fig. 1

From: Protection against inhalation anthrax by immunization with Salmonella enterica serovar Typhi Ty21a stably producing protective antigen of Bacillus anthracis

Fig. 1

Antibodies in mice immunized with Ty21a-PA01. Mice were vaccinated with 5 × 107 CFU of Ty21a (triangles) or Ty21a-PA-01 (squares) by intraperitoneal (IP) injection at 2-week intervals. Sera collected at 2 weeks after dose 3 were assayed for anti-PA IgG by ELISA (a) and anthrax toxin neutralization activity (TNA) (b). Antibody responses by ELISA are reported as the serum dilution at which the optical density was 1.0 (OD 1.0), and TNA titers as the last serum dilution at which there was 50% protective activity against killing of macrophages (J774A.1) by LT. Filled symbols represent mice that were not protected in the spore challenge study and open symbols represent those that were protected (see Fig. 3). The geometric mean of each group is shown as a horizontal line. Antibody responses between the two groups were analyzed by Mann–Whitney U test (p = 1.1 × 10−5 and 8.2 × 10−6 for ELISA and TNA, respectively)

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