Safety and Immunogenicity of DAPTACEL® as 5th Dose in Children 4 to 6 Years Old After 4 Doses of Pentacel™ or DAPTACEL®

Primary Objectives: 1. To present the safety profile after a 5th dose of DAPTACEL® in children 4 to 6 years of age who have previously received 4 doses of DAPTACEL® or Pentacel™. 2. To present the pre-Dose 5 and post-Dose 5 antibody responses to the antigens in DAPTACEL® in children 4 to 6 years of age who have previously received 4 doses of DAPTACEL® or Pentacel™. Observational Objectives: 1. To compare under equivalence criteria the pre-Dose 5 and post-Dose 5 antibody responses to the antigens in DAPTACEL® in children 4 to 6 years of age who have previously received 4 doses of DAPTACEL® or Pentacel™. 2. To present the pre-vaccination anti-poliovirus GMTs and seroprotection rates. 3. To present the post-vaccination anti-poliovirus GMTs and seroprotection rates among subjects receiving a 4th dose of IPV concurrently with the 5th dose of DAPTACEL and a 2nd dose of MMR.