What is Hib?

Haemophilus influenzae (including Hib) is a bacterium that can cause a severe infection, occurring mostly in infants and children younger than five years of age. In spite of its name, Haemophilus influenzae does not cause influenza (the "flu"). It can cause lifelong disability and be deadly.

There are six identifiable types of Haemophilus influenzae bacteria (a through f) and other non-identifiable types (called nontypeable). The one that most people are familiar with is Haemophilus influenzae type b, or Hib. There’s a vaccine that can prevent disease caused by Hib, but not the other types of Haemophilus influenzae.

Most of the time, Hib is spread by people who have the bacteria in their noses and throats but who are not ill (asymptomatic).

Hib can also cause epiglottitis and pneumonia. Other forms of invasive Hib disease include blood, bone, or joint infections. Hib disease is very serious. As many as one out of 20 children with Hib meningitis dies, and it causes permanent brain damage or deafness in one out of five survivors.

About the Hib Vaccination

Hib vaccine is recommended for all children under five years old in the United States, and it is usually given to infants starting at two months old. The Hib vaccine can be combined with other vaccines. Some brands of vaccine contain Hib along with other vaccines in a single shot.