Haemophilus influenzae type b capsular polysaccharide conjugated to Neisseria meningitidis outer membrane protein (PRP-OMP or Hib-OMP)

Haemophilus influenzae type b capsular polysaccharide conjugated to Neisseria meningitidis outer membrane protein (PRP-OMP) is a molecular antigen used in some Hib vaccines, including PedvaxHIB. The Hib bacteria have a polysaccharide capsule (polyribosyl ribitol phosphate, PRP), which itself elicits a weak immune response in infants. By chemically linking PRP to a protein carrier (in this case, an outer membrane protein from Neisseria meningitidis), the conjugate vaccine is able to induce a robust, T-cell-dependent immune response with strong and long-lasting immunological memory, effectively preventing invasive Hib disease in children. PRP-OMP is not a drug target in the sense of a therapeutic receptor or enzyme, but rather is an antigen used to stimulate immune protection against Hib infection in pediatric populations.

Other names

Haemophilus influenzae type b conjugate vaccine (Hib conjugate vaccine)Hib vaccine (with Neisseria meningitidis outer membrane protein as carrier protein)PRP-OMPPedvaxHIB (brand name in the United States)Haemophilus influenzae type b capsular polysaccharide-Neisseria meningitidis outer membrane protein conjugate

The PRP polysaccharide (from Hib) is covalently linked to Neisseria meningitidis outer membrane protein (carrier). This conjugation transforms a weak T-independent antigen into a potent T-dependent antigen that elicits strong adaptive immunity, including antibody generation and memory B cell formation. Upon administration, the vaccine induces anti-PRP antibodies, which provide protection against future Hib infection.