Impact of Haemophilus influenzae type b vaccines on the epidemiology of bacterial meningitis.

Haemophilus influenzae type b (Hib) was the most common cause of bacterial meningitis in the United States in the 1980s. Although introduction of Hib polysaccharide vaccines had little impact on disease incidence, development and use of Hib polysaccharide-protein conjugate vaccines dramatically reduced Hib meningitis rates. With widespread use of the new Hib conjugate vaccine, elimination of Hib meningitis in the United States may be achieved. Development of similar vaccines for other bacterial agents of meningitis are in progress.