Study of DAPTACEL® Administered as a 5th Dose in 4 to 6-Year-Old Children Previously Immunized With PENTACEL™

This study is designed to assess the safety and immunogenicity of DAPTACEL® vaccine
administered at 4 to 6 years of age according to the US standard of care. The study
population consists of PENTACEL™-primed subjects from Aventis Pasteur's pivotal studies
494-01 and 494-03. These children will receive DAPTACEL® vaccine as a 5th dose immunization
between 4 to 6 years of age.

Inclusion Criteria :

- Aged ≥ 4 years and 6 years.

- Signed and dated Investigational Review Board-approved informed consent from a parent
or legally authorized representative.

- 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 4th dose in Study 494-01 or Study 494-03,
consisting of four previous administrations of PENTACEL™.

Exclusion Criteria :

- Received a 5th dose of DTaP-containing vaccine scheduled at 4 to 6 years of age.

- Serious underlying chronic disease, including, but not limited to:

- Diabetes mellitus; malignancy; cardiopulmonary disease; renal, endocrinologic, or
hepatic dysfunction; or hematologic disorder; or

- Unstable or evolving neurologic disorders that may predispose the subject to seizures
or neurologic deterioration.

- Known or suspected primary or acquired disease of the immune system.

- Administration of immune globulin or other blood products within the last 3 months,
or injected or oral corticosteroids or other immunomodulatory therapy within 6 weeks
of the study vaccine. 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
the last 4 weeks.

- Receipt of any other vaccine within the past 30 days, or planning to receive another
vaccine within 30 days before the Visit 2 blood draw, with the exclusion of M-M-R®II
and IPV.

- 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.

Temporary contraindications:

- A subject who meets either of the following criteria at the time of planned
vaccination will have enrollment deferred until complete resolution of symptoms:

Oral temperature ≥ 100.4°F (≥ 38.0ºC) (Note: A tympanic thermometer should not be used).

- Any moderate or severe acute illness with or without fever.