The Difference Between Hib-HbOC and Hib PRP-T

Hib-HbOC and Hib PRP-T are both Type B Haemophilus influenzae vaccines for intramuscular use. The Advisory Committee on Immunization Practices (ACIP) recommends all infants be administered one of these types of vaccines routinely by the age of two months and as early as six weeks. HbOC is a small polysaccharide while PRP-T is a medium polysaccharide; the vaccines differ in the type of protein carrier used for administration.

History of Haemophilus Influenzae

• Haemophilus influenzae, or Hib, is the primary cause of invasive bacterial disease in children in the U.S. Prior to the creation of the Hib-HbOC and Hib PRP-T vaccines, one in 200 children developed the disease before the age of five, including 60 percent who contracted meningitis with a mortality rate of 3 to 6 percent. Known side effects of the Hib vaccines include inflammation or discomfort in about one in 20 patients and fever in about one in 50. These side effects usually subside within 24 hours.

Hib PRP-T Specifications

• Hib PRP is an inactivated polysaccharide bacterial vaccine that contains between 7.5 and 10 micrograms of Hib polyribosylribitol phosphate polysaccharide. This means, essentially, that it contains destroyed virus particles that will cause a response in the immune system. The vaccine is also supplied with a protein carrier to encourage its recognition and incorporation in the body. The carrier used in PRP-T is a tetanus toxoid. PRP-T is available as a monodose vaccine exclusively for treating Hib, or it can be combined in dosage with other vaccines for treating hepatitis B, polio, diptheria, tetanus and pertussis.

Hib-HbOC Specifications

• The Hib-HbOC vaccine was manufactured in the United States in 1990 and was discontinued for use in 2007 due to less favorable results in comparison to newer Hib drugs; thus it is no longer offered as an immunization option. The vaccine was comprised of oligosaccharides, with a protein carrier that contained Corynebacterium diphtheriae -- a combination of diphtheria and tetanus toxoids. Doses were designed to be administered no less than two months apart.

Availability and Use

• Hib PRP-T is known by the brand names ActHIB® -- manufactured by Sanofi Pasteur -- and Hiberix® -- manufactured by GlaxoSmithKline. Hib-HbOC was known by the brand name HibTITER®. With both PRP-T and HbOC, a full four-dose cycle has been suggested rather than a single vaccination although this may vary depending on the age of the patient. Though the HbOC vaccine has been discontinued in the U.S., the PRP-T in both brands is still available.