Haemophilus influenzae type b polysaccharide-tetanus toxoid conjugate

The Haemophilus influenzae type b (Hib) polysaccharide-tetanus toxoid conjugate is a vaccine component designed to prevent infections caused by the bacterium *Haemophilus influenzae* type b. This bacterium can cause severe, potentially life-threatening diseases such as meningitis, epiglottitis, pneumonia, pericarditis, and septic arthritis. The active component consists of the capsular polysaccharide from *H. influenzae* type b (specifically polyribosylribitol phosphate or PRP), which is covalently linked to a carrier protein—tetanus toxoid in this case. This conjugation transforms the otherwise poorly immunogenic polysaccharide into a form that elicits a strong T-cell dependent immune response. Upon administration, antigen-presenting cells process the conjugated molecule; peptides from tetanus toxoid are presented via MHC class II molecules to CD4+ T helper cells. These T cells then provide help to B cells specific for PRP through costimulatory interactions (such as CD40–CD40L), leading to robust antibody production with class switching and memory formation.

Other names

Hib polysaccharide-tetanus toxoid conjugatePRP-tetanus toxoid conjugate

Induces robust antibody response via T cell-dependent activation