On Dec. 21, 1988, the conjugated Haemophilus influenzae type b vaccine (HibTITER by Wyeth-Lederle) was licensed.

Prior to the introduction of the Hib vaccine, approximately 1 in 200 young children in the United States developed Hib invasive infection before their fifth birthday annually, representing 12 000 cases of Hib meningitis per year.