Haemophilus influenzae type b capsular polysaccharide conjugated to Neisseria meningitidis outer membrane protein complex (Hib-OMPC)

Haemophilus influenzae type b capsular polysaccharide conjugated to Neisseria meningitidis outer membrane protein complex (Hib-OMPC) is a vaccine antigen designed to prevent invasive Hib disease. The target consists of the polyribosylribitol phosphate (PRP) polysaccharide from Hib covalently linked to the outer membrane protein complex (OMPC) of Neisseria meningitidis serogroup B (FDA, 2011). This conjugation is critical because pure PRP is a T-cell independent antigen that is poorly immunogenic in infants; the OMPC carrier provides T-cell epitopes that convert the response to T-cell dependent, enabling the induction of high-affinity IgG antibodies and long-term immunological memory (StatPearls, 2023). Hib-OMPC is specifically noted for its ability to induce a protective antibody response after a single dose in young infants (CDC, 2022). It is used to protect against life-threatening conditions such as bacterial meningitis, epiglottitis, and pneumonia caused by Hib (PubMed, 2021). The interaction with the host immune system involves antigen-presenting cells processing the OMPC and presenting peptides to T-helper cells, which then stimulate B-cells specific to the PRP polysaccharide (NIH, 2020).

Other names

PRP-OMPHib-OMPPolyribosylribitol phosphate-outer membrane protein conjugatePedvaxHIBHaemophilus b Conjugate Vaccine (Meningococcal Protein Conjugate)

The conjugate acts as an antigen that triggers a T-cell dependent immune response. The polysaccharide component (PRP) provides the B-cell epitope, while the protein carrier (OMPC) provides T-cell epitopes, leading to B-cell activation, class switching to IgG, and memory B-cell production.