Background: Tetanus-reduced dose diphtheria-acellular pertussis (Tdap) vaccination during adolescence was\nintroduced in response to the resurgence of pertussis in various countries. A new Tdap vaccine was manufactured\nin Korea as a countermeasure against a predicted Tdap vaccine shortage. This study was performed to evaluate the\nimmunogenicity, safety, and protection efficacy against Bordetella pertussis of the new Tdap vaccine in a murine\nmodel.\nMethods: Four-week-old BABL/c mice were used for assessment of immunogenicity and protection efficacy. A\nsingle dose of primary diphtheria-tetanus-acellular pertussis (DTaP) vaccine was administered, followed by a single\ndose of Tdap booster vaccine after a 12-week interval. Anti-pertussis toxin (PT), anti-filamentous hemagglutinin\n(FHA), and anti-pertactin (PRN) IgG titers were measured before primary vaccination, and before and after booster\nvaccination. An intranasal challenge test was performed after booster vaccination to determine protection efficacy.\nTo assess safety, mouse weight gain test and leukocytosis promotion test were performed using 4-week-old ddY\nfemale mice.\nResults: Anti-PT and anti-FHA IgG titers after booster vaccination were significantly higher than those before\nbooster vaccination with either the new vaccine or a commercially available Tdap vaccine (P = 0.01 for all\noccasions). After booster vaccination, no significant difference was observed between the two vaccines in antibody\ntiters against pertussis antigens (P = 0.53 for anti-PT IgG, P = 0.91 for anti-FHA IgG, P = 0.39 for anti-PRN IgG). In the\nintranasal challenge test, inoculated B. pertussis was eradicated 7 days after infection. On days 4 and 7 after\ninfection, colony counts of B. pertussis were not significantly different between the new and positive control\nvaccine groups (P = 1.00). Mean body weight changes and leukocyte counts of the new vaccine, positive control,\nand negative control groups were not significantly different 7 days after vaccination (P = 0.87 and P = 0.37,\nrespectively). All leukocyte counts in the new vaccine group were within a mean �± 3 standard deviations range. Conclusions: A murine model involving a single dose primary DTaP vaccination followed by a single dose Tdap\nbooster vaccination can be used for non-clinical studies of Tdap vaccines. The new Tdap vaccine manufactured in\nKorea exhibited comparable immunogenicity, protection efficacy, and safety with a commercially available Tdap\nvaccine.
Loading....