FDA licensed Pentacel in 2008 as a 4-dose series in infants and children at ages 2, 4, 6, and 15–18 months. It should not be used for any dose in the primary series for children age 5 years or older or as the booster dose for children ages 4 through 6 years. The DTaP-IPV component is supplied as a sterile liquid, which is used to reconstitute lyophilized (freeze-dried) ActHIB vaccine. The two components of the vaccine should be stored together in the carton to reduce the chance of giving one component of the vaccine without the other. The DTaP-IPV component should never be administered alone.