The pediatric combination vaccine -- approved for use in infants and children 6 weeks through 4 years of age -- is indicated for active immunization against diphtheria, tetanus, pertussis, poliomyelitis, and invasive disease due to Haemophilus influenza type b (Hib). It contains no thimerosal.

Pentacel vaccine is approved for administration as a four-dose series at 2, 4, 6 and 15 to 18 months of age. The first dose may be given as early as 6 weeks of age.

The current recommended childhood immunization schedule of the U.S. Centers for Disease Control and Prevention in Atlanta says up to 23 injections are needed by the time a child reaches 18 months of age with single-entity vaccines, however, the use of the Pentacel vaccine could reduce that number of shots by seven, said Wayne Pisano, president and chief executive officer of Sanofi Pasteur.

Pisano said the current recommended childhood immunization schedule of the U.S. Centers for Disease Control and Prevention in Atlanta says up to 23 injections are needed by the time a child reaches 18 months of age with single-entity vaccines.

However the use of the Pentacel vaccine -- already approved in Canada for a decade -- could reduce that number of shots by seven.