Haemophilus influenzae type b capsular polysaccharide–protein conjugate (Hib polysaccharide–protein conjugate)

Haemophilus influenzae type b capsular polysaccharide–protein conjugate is not a biological target (such as an endogenous receptor, transporter, or enzyme), but rather a type of vaccine antigen used in the prevention of invasive disease caused by Haemophilus influenzae type b (Hib). The conjugate consists of the purified capsular polysaccharide from Hib (polyribosyl-ribitol-phosphate, PRP) chemically linked (conjugated) to a carrier protein such as tetanus toxoid or meningococcal outer membrane protein. This conjugation increases immunogenicity in infants and young children by enabling T cell–dependent immune responses, leading to the generation of protective anti-PRP antibodies. The conjugate itself is the active component of several Hib vaccines (e.g., Hiberix, ActHIB, PedvaxHIB), administered to young children to provide immunity and prevent severe illnesses such as meningitis, sepsis, and pneumonia due to Hib infection. Protection correlates with the level of serum anti-PRP antibodies, with a recognized threshold for protective immunity. Note: This entry does not describe an endogenous molecule or a therapeutic target such as a receptor or enzyme, but rather a vaccine antigen. If a biological or pharmacological target is desired, the entry should be for a specific host receptor or microbial virulence factor, not the vaccine conjugate itself.

Other names

Haemophilus influenzae type b conjugatePRP–protein conjugateHib conjugatePRP-T (if conjugated to tetanus toxoid)PRP-OMP (if conjugated to meningococcal outer membrane protein)

Null (not a drug target; see description)