Polyribosyl ribitol phosphate

Dual-chamber syringe. For delivery of two established vaccines (e.g., polyribosyl ribitol phosphate conjugated to tetanus toxoid and diphtheria-tetanus-whole cell pertussis and inactivated poliovirus vaccine) at the same time, a dual-chamber syringe delivery system can be used. The proximal chamber may contain a vaccine in the freeze-dried solid state, and the distal chamber contains a vaccine in the liquid formulation that allows reconstitution of the vaccine in the proximal chamber. The immune response by the dualchamber delivery of vaccination was equivalent to that by the separate-injection method of vaccination. The dual-chamber syringe can be used for safe and effective delivery of two different vaccines that are not yet available as a single formulation for pediatric applications. ... 

Before 1995, H. influenzae type b (Hib) was responsible for thousands of cases of serious illnesses (e.g., meningitis, epiglottitis, pneiunonia, sepsis, and septic arthritis). The incidence of Hib disease has declined more than 99% since introduction of the conjugate vaccines based on the organism s capsular substance, polyribosyl ribitol phosphate (PRP).32... 

Four different vaccines for Hib are licensed in the United States. All these vaccines are composed of Hib capsular polysaccharide conjugated to a protein carrier. All four vaccines use a different carrier. Polyribosyl ribitol phosphate (PRP) capsule is an important virulence factor that renders Hib resistant to phagocytosis by neutrophils in the absence of specific anti-capsular antibody. Antibody directed against PRP capsule of Hib is primarily responsible for host resistance to infection. The Hib vaccine is composed of the purified, capsular polysaccharide of Hib. Antibodies to this antigen correlate with protection against invasive disease. 

The solid-phase synthesis of a hexameric polyribosyl ribitol phosphate fragment has been achieved with compounds 56, 57, and 58, respectively, as chain-initiation-, chain-propagation-, and chain-terminating-linker-monomers. ... 

---