Haemophilus b Conjugate Vaccines

Publisher Summary This chapter discusses Haemophilus b conjugate vaccines. Haemophilus influenzae type b (Hib), an encapsulated, Gram-negative, rod-like bacterium, is responsible for an estimated 10,000 cases of meningitis per year in the United States. Other invasive Hib infections, such as septicemia, epiglottitis, cellulitis, septic arthritis, pneumonia, otitis media, osteomyelitis, and pericarditis can also occur, bringing the total number of invasive Hib infections in the United States to at least 20,000 cases annually. There is considerable evidence that antibodies to the Hib capsular polysaccharide are protective. The biological properties of these antibodies include complement activation for opsonic and bactericidal activity, and protection of infant rats from bacteremia and subsequent meningitis following challenge with virulent Hib organisms. In 1985, the first Hib vaccine, composed of purified PRP, was licensed in the United States.