You may never have heard of Haemophilus influenzae type b, or "Hib" disease. For some reason Hib disease has never become as well known as other childhood diseases, but it is just as dangerous. As recently as the mid-1980's, Hib disease struck one child out of 200 under 5 years old in the United States. Every year about 12,000 children got meningitis (inflammation of the covering of the brain) as a result of Hib. In fact, Hib disease was the leading cause of bacterial meningitis in children under five. About 1 in 4 of these children suffered permanent brain damage, and about 1 in 20 died. In addition, about 8,000 children a year suffered from other serious complications, such as pneumonia.Hib vaccine has had a dramatic impact on Haemophilus influenzae type b. As soon the first vaccine came into use in 1985 the disease began to disappear. Several improved vaccines have been licensed since then, and the age for the first shot has been lowered from 24 months to 2 months. There were an estimated 20,000 cases of Hib disease a year in the mid-1980's, but now there are only a few hundred cases a year.