Immunogenicity and safety of a trivalent tetanus, low dose diphtheria, inactivated poliomyelitis booster compared with a standard tetanus, low dose diphtheria booster at six to nine years of age

Objective. To compare the immunogenicity and safety of a trivalent tetanus- diphtheria (low toroid content)-inactivated poliomyelitis vaccine, Td-IPV ( Revaxis; Pasteur Merieux), with a tetanus-diphtheria (low toroid content) v accine, Td (Td-Impfstoff Merieux; Pasteur Merieux), when administered as a booster to children age 6 to 9 years. Methods. A group of 301 children were randomized and vaccinated with Td IPV (n = 150) or Td (n = 151) in this open, controlled, multicenter trial, Ser um specimens were obtained before and 28 days after vaccination. Safety was assessed for up to 28 days postvaccination by parental diary cards. Solici ted local and systemic reactions were recorded for 7 days after vaccination . Results, Seroprotection (enzyme-linked immunosorbent assay titer, greater t han or equal to 0.10 IU/ml) against tetanus and diphtheria was induced by e ither Td-IPV or Td in all subjects. Tetanus and diphtheria geometric mean t iter were higher after Td (34.0 and 5.74 IU/ml) than after Td-IPV (15.9 and 4.38 IU/ml), All subjects boosted with Td-IPV were seroprotected against e ach type of poliovirus (neutralizing antibody titer, greater than or equal to 5/dilution). The most frequently reported solicited local and systemic s ymptoms were pain triggered by movement of the arm (54% vs. 39.1%) and head ache (17.3% vs. 7.3%), after Td-IPV and Td,respectively, All other events w ere similar between the two groups, Reactions were generally mild and all w ere temporary. Conclusions, A booster dose of Td-IPV induced in all children seroprotectio n against tetanus, diphtheria and poliomyelitis. The overall safety profile of the two vaccines was acceptable.