In short
N. meningitidis group C polysaccharide is a bacterial sugar molecule used as the active ingredient in vaccines against meningococcal disease caused by Neisseria meningitidis serogroup C. It is available in authorised vaccines such as NeisVac-C, where it is conjugated to tetanus toxoid protein to improve the immune response. One registered clinical trial (NCT06989359) lists this substance as part of the Nimenrix vaccine, which also covers meningococcal groups A, W-135 and Y.
Key points
- N. meningitidis group C polysaccharide is the active component of conjugate vaccines against meningococcal group C disease.
- It is conjugated to tetanus toxoid protein in the authorised vaccine NeisVac-C to strengthen the immune response.
- The substance appears in Nimenrix, a vaccine covering meningococcal groups A, C, W-135 and Y.
- One registered trial, NCT06989359, is a Phase 2 study in complement-mediated kidney disease with 45 participants.
- The trial is currently authorised and measures the incidence and severity of treatment-emergent adverse events.
What is N. meningitidis group C polysaccharide?
N. meningitidis group C polysaccharide is a capsular polysaccharide antigen derived from the bacterium Neisseria meningitidis group C. It is the active component of meningococcal group C conjugate vaccines, including NeisVac-C, where it is conjugated to tetanus toxoid protein and adsorbed onto aluminium hydroxide. The substance is also a component of Nimenrix, a vaccine covering meningococcal groups A, C, W-135 and Y, in which the polysaccharide is conjugated to tetanus toxoid protein.
How does N. meningitidis group C polysaccharide work?
The polysaccharide antigen is conjugated to a carrier protein, tetanus toxoid, which converts the immune response from a T-cell-independent to a T-cell-dependent one. This conjugation enhances immunogenicity, particularly in infants and young children, and promotes immunological memory. The vaccine stimulates the production of antibodies against the group C capsular polysaccharide of Neisseria meningitidis, protecting against invasive meningococcal disease caused by this serogroup.
Which conditions is it used or studied for?
- Meningococcal group C disease — invasive infections such as meningitis and septicaemia caused by Neisseria meningitidis serogroup C.
- Complement-mediated kidney disease — the registered trial NCT06989359 lists Nimenrix, which contains this substance, among the vaccines being administered in a Phase 2 study in this condition.
How is N. meningitidis group C polysaccharide given?
As part of authorised vaccines, the substance is given by intramuscular injection. NeisVac-C is supplied as a suspension in a prefilled syringe of 0.5 ml. Nimenrix is supplied as a powder and solvent for solution for injection in a prefilled syringe, also given intramuscularly at 0.5 ml. A polysaccharide A and C vaccine formulation has also been described for intramuscular or subcutaneous use.
What do the clinical trials show?
One registered clinical trial includes N. meningitidis group C polysaccharide as part of the Nimenrix vaccine. The trial, NCT06989359, is a Phase 2 study evaluating the safety and tolerability of ADX-038 in complement-mediated kidney disease. It has 45 participants and is currently authorised. The primary outcome is the incidence and severity of treatment-emergent adverse events (TEAEs). In this trial, Nimenrix is one of several vaccines administered to participants, alongside Prevenar 20, Infanrix hexa and Bexsero.
What side effects are known?
The supplementary sources provided do not list specific side effects for this substance. The registered trial NCT06989359 measures the incidence and severity of treatment-emergent adverse events as its primary outcome, but results are not yet available.