These vaccines are prepared from the purified capsule of Haemophilus influenzae type b (Hib). All Hib vaccines use polyribosylribitol phosphate (PRP) as the polysaccharide, but 4 different protein carriers are used in the 4 different Hib conjugate vaccines available:

PRP-D and HbOC vaccines are no longer available in the US.

Combination vaccines that contain Hib conjugate vaccine include DTaP-IPV/Hib (Pentacel®), Hib-HepB (COMVAX®), and Hib-MenCY (MenHibrix®).

Some Hib vaccines—PRP-T (ActHIB®, Pentacel®, or MenHibrix®) and PRP-OMP (PedvaxHIB® or COMVAX®)—can be used in infants as young as 6 wk. Another Hib vaccine (Hiberix®) can be used only for the last dose of the Hib schedule in children ≥ 12 mo.

The Hib vaccine is a routine childhood vaccination (see Table: Recommended Immunization Schedule for Ages 0–6 yr).

This vaccine is also recommended for

The main contraindication is

The main precaution is

Hib vaccine 0.5 mL is given IM. A primary childhood series is given in 3 doses at age 2, 4, and 6 mo or in 2 doses at age 2 and 4 mo, depending on the formulation. In either case, a booster is recommended at age 12 to 15 mo.

One dose is given to older children, adolescents, and adults who have asplenia or who are scheduled for an elective splenectomy if they are unimmunized. Some experts suggest giving a dose before elective splenectomy regardless of vaccination history. The dose is given ≥ 14 days before elective splenectomy if possible.

A 3-dose regimen is given 6 to 12 mo after hematopoietic stem cell transplantation; doses are separated by ≥ 4 wk.

Adverse effects are rare. They can include pain, redness, and swelling at the injection site and, in children, fever, crying, and irritability.