On Sept. 27, 1996, the Food and Drug Administration (FDA) licensed a Haemophilus b Conjugate Vaccine (ActHIB) combined by reconstitution with diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP) (Tripedia) for use as the fourth dose in the childhood vaccination series.

This combination vaccine was sold under the trade name TriHIBit. On July 31, 1996, Tripedia was licensed for the initial four doses of the diphtheria, tetanus, and pertussis vaccination series (1). TriHIBit is the first vaccine to be licensed in the United States that combines DTaP with a Haemophilus b Conjugate Vaccine.