The Haemophilus influenzae type b (Hib) vaccine helps protect against bacterial infections due to Hib, such as pneumonia and meningitis. These infections may be serious in children. Use of the vaccine has decreased the incidence of serious Hib infections in children by 99%. These infections are uncommon in adults with a healthy immune system and a functioning spleen.
Vaccine Type
Different formulations of the vaccine are available.
All Hib vaccines are polysaccharide conjugate vaccines, which means they contain a piece of the bacteria that does not cause infection and a specific protein component from another bacteria. Because these components are harmless, they cannot cause Hib infection, but they do trigger a strong response from a person's immune system (see Active immunization).
Combination vaccines that contain Hib, hepatitis B, inactivated poliovirus, and diphtheria-tetanus-pertussis (DTaP) are also available.
Dose of and Recommendations for Haemophilus influenzae Type b Vaccine
All Hib vaccines are injected into a muscle.
People who should get this vaccine
Hib vaccine is a routine childhood vaccination. Two separate doses are given at age 2 months and 4 months or 3 separate doses are given at age 2 months, 4 months, and 6 months, depending on which formulation is used. In either case, a booster dose is given at age 12 to 15 months (for a total of 3 or 4 doses). (See Centers for Disease Control and Prevention [CDC]: Recommended Immunizations for Birth Through 6 Years Old, United States, 2025). Sometimes children need additional doses, for example, children who are going to receive chemotherapy, radiation, a stem cell transplant or who have HIV infection.
All children should be vaccinated.
The Hib vaccine is also recommended for people who are at increased risk of this infection:
People who do not have a spleen or their spleen does not work well and they have not been vaccinated
People who have had stem cell transplantation even if they have been vaccinated
(See also CDC: Recommended Immunizations for Adults Aged 19 Years and Older, United States, 2025.)
People who should not get this vaccine
People who have had a serious, life-threatening allergic reaction (such as an anaphylactic reaction) to any component in a Hib vaccine should not receive it.
Infants under 6 weeks of age should not receive a Hib vaccine.
If people have a temporary illness, doctors usually wait to give the vaccine until the illness resolves (see also CDC: Who Should NOT Get Vaccinated With These Vaccines?).
Side Effects of Haemophilus influenzae Type b Vaccine
Occasionally, side effects may include soreness, swelling, and redness at the injection site.
After being vaccinated, children may have a fever, cry, and be irritable.
For more information about side effects, see the package inserts.
More Information
The following English-language resources may be useful. Please note that The Manual is not responsible for the content of these resources.
Centers for Disease Control and Prevention (CDC): Haemophilus Influenzae type b (Hib) vaccine information statement
European Centre for Disease Prevention and Control (ECDC): Haemophilus Influenzae Type B Infection: Recommended vaccinations
