Haemophilus influenzae type b conjugate vaccine helps prevent Haemophilus infections that are caused by serotype b but not infections caused by other serotypes of H. influenzae bacteria. H. influenzae causes many childhood infections, including bacteremia, meningitis, pneumonia, sinusitis, otitis media, and epiglottitis.
(See also Overview of Immunization.)
Preparations of Hib Vaccine
Haemophilus influenzae type b conjugate vaccines (Hib) are prepared from the purified capsule of H. influenzae type b. 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:
Diphtheria toxoid (PRP-D)
Neisseria meningitidis outer membrane protein (PRP-OMP)
Tetanus toxoid (PRP-T)
Diphtheria mutant carrier protein CRM197 (HbOC)
PRP-D and HbOC vaccines are no longer available in the United States.
Combination vaccines with hepatitis B (HepB), inactivated poliovirus (IPV), and the diphtheria/tetanus toxoids/pertussis vaccine (DTaP) are also available in the United States: DTaP-IPV-Hib and DTaP-IPV-Hib-HepB.
Indications for Hib Vaccine
The Hib vaccine is a routine childhood vaccination. The Centers for Disease Control and Prevention (CDC) recommends Hib vaccination for all children < 5 years old; those < 1 year old need multiple (2 or 3) doses of a Hib vaccine.
Children who are to receive chemotherapy, radiation treatment, or a hematopoietic stem-cell transplant; have anatomic or functional asplenia (including sickle cell disease); or are about to undergo elective splenectomy may require further doses (1). Children with HIV infection, immunoglobulin deficiency, or early component complement deficiency (because of the risk of meningitis) may also receive further doses (2, 3).
People> 5 years old do not routinely require Hib vaccination, except for those in specific high-risk groups such as the following (4):
Adults with anatomic or functional asplenia and those scheduled for elective splenectomy
People who have had a hematopoietic stem cell transplantation regardless of their vaccination history
Indications references
1. CDC. Hib Vaccine Recommendations. Accessed September 23, 2025.
2. CDC. Child and Adolescent Immunization Schedule by Age. Accessed September 23, 2025.
3. CDC. Haemophilus influenzae type b vaccination: Special situations. Accessed September 23, 2025.
4. CDC. Adult Immunization Schedule by Age. Accessed September 23, 2025.
Contraindications and Precautions for Hib Vaccine
The main contraindications for Hib vaccines are the following:
A severe allergic reaction (eg, anaphylaxis) after a previous dose or to a vaccine component
Infant age < 6 weeks
The main precaution for Hib vaccines is:
Moderate or severe illness with or without a fever (vaccination is postponed until the illness resolves)
Dose and Administration of Hib Vaccine
The Hib vaccine dose is 0.5 mL IM. A primary childhood series is administered in 3 doses at age 2, 4, and 6 months or in 2 doses at age 2 and 4 months, depending on the formulation. In either case, a booster is recommended at age 12 to 15 months.
One dose is administered 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 administered ≥ 14 days before elective splenectomy if possible.
A 3-dose regimen is administered 6 to 12 months after hematopoietic stem cell transplantation; doses are separated by ≥ 4 weeks.
Adverse Effects of Hib Vaccine
Adverse effects are rare. They can include pain, erythema, warmth, and swelling at the injection site and, in children, fever, crying, and irritability.
For more information about adverse effects of these vaccines, refer to the prescribing information.
More Information
The following English-language resource may be useful. Please note that The Manual is not responsible for the content of this resource.
Advisory Committee on Immunization Practices (ACIP): ACIP Recommendations: Haemophilus influenzae Type B (Hib) Vaccine
Centers for Disease Control and Prevention (CDC): Hib (Haemophilus influenzae type b)
European Centre for Disease Prevention and Control (ECDC): Haemophilus Influenzae Type B Infection: Recommended vaccinations
