Inclusion Criteria:

• Aged >=4 and <7 years from date of birth at the time of study vaccination
• Signed and dated Investigational Review Board (IRB)-approved informed consent from a parent or legally authorized representative. Signed and dated IRB-approved assent from subject if required by IRB
• Judged to be in good health on the basis of reported medical history and physical examination
• Able and willing to attend the scheduled visits and to comply with the study procedures
• Has documented complete infant series and the 4th dose of DAPTACEL® or Pentacel™ in Study P3T06 (i.e., 4 previous administrations of DAPTACEL® or Pentacel™).

Exclusion Criteria:

• Received a 5th dose of DTaP-containing vaccine
• a. For subjects in the DAPTACEL® arm: Received a 4th dose of IPV vaccine and/or a 2nd dose of MMR vaccine scheduled at 4 to 6 years of age. b. For subjects in the Pentacel™ arm: Received a 2nd dose of MMR vaccine scheduled at 4 to 6 years of age
• Severe hypersensitivity to any component of the vaccine such as an anaphylactic reaction observed following a previous vaccination
• Serious underlying chronic disease, including, but not limited to:·Diabetes mellitus; malignancy; cardiopulmonary disease; renal, endocrinologic, or hepatic dysfunction; or hematologic disorder·Unstable or evolving neurologic disorders that may predispose the subject to seizures or neurologic deterioration. These may include progressive neurologic disorders (e.g., infantile spasms, uncontrolled progressive encephalopathy) and encephalopathy within 7 days following previous vaccination
• Known or suspected primary or acquired disease of the immune system
• Administration of immune globulin, other blood products within the last 3 months, injected or oral corticosteroids or other immunomodulator therapy within 6 weeks prior to study vaccination. Individuals on a tapering dose schedule of oral steroids lasting <7 days may be included in the trial as long as they have not received more than 1 course within the last 2 weeks prior to enrollment
• Had allergy shots started or had changes in regimen or dosing of allergy shots within 4 weeks prior to study vaccination
• Receipt of any other vaccine within 30 days prior to study vaccination, or planning to receive another vaccine within 30 days before the Visit 2 blood draw (if applicable)
• Any other condition which, in the opinion of the investigator, would pose a health risk to the subject or interfere with the evaluation of the vaccine
• Enrolled in another vaccine trial
• Personal history of physician-diagnosed or laboratory-confirmed pertussis disease within the past 30 months
• Known or suspected allergy to any of the vaccines or vaccine components intended for use in this study.