Haemophilus Influenzae

About Haemophilus Influenzae

The Haemophilus influenzae type b Hib vaccine prevents bacterial meningitis and other invasive diseases. Before the vaccine, Hib caused an estimated 20,000 cases of invasive disease annually in the US, mostly in children under 5. A small percentage of Hib meningitis cases were fatal and a substantial share of survivors had permanent neurological damage. The first Hib polysaccharide vaccine was licensed in 1985 but was ineffective in infants under 18 months. Conjugate vaccines, licensed starting in 1987, were effective in infants. WHO policy supports Hib conjugate vaccine in routine immunization programs. Hib vaccination has reduced invasive Hib disease by around 99 percent in some vaccinated populations, including the US. Hib vaccine is typically combined with other vaccines in pentavalent or hexavalent formulations for easier administration.