Recently, great progress has been made in the development of vaccines against Hib. Four polysaccharide-protein conjugate vaccines are actively being tested. Three of these (PRP-D, HbOC, and PRP-OMP) are currently licensed for use in children at 15-18 months of age. Clinical trials of these vaccines in infants are currently being conducted in the United States. If these show the vaccines to be efficacious, licensure for infants will follow. Although much work remains to be done, it seems likely that the effective prevention of serious Hib infections in infants, as well as in older children, is a goal that may be within our reach in the next several years.