In short
Pneumococcal oligosaccharide serotype 18C conjugated to CRM197 is one of fifteen pneumococcal polysaccharide components of Vaxneuvance, an authorised pneumococcal conjugate vaccine. It is studied as part of this vaccine in a Phase 3 trial with 1,113 healthy infants, where Vaxneuvance serves as the comparator against an investigational 21-valent vaccine. The trial measures antibody responses to pneumococcal serotypes.
Key points
- Pneumococcal oligosaccharide serotype 18C is a component of Vaxneuvance, an authorised 15-valent pneumococcal conjugate vaccine.
- The substance is given as a suspension for injection by intramuscular injection.
- It is studied in a Phase 3 trial in 1,113 healthy infants from approximately 2 months of age.
- The trial compares Vaxneuvance (15-valent) against an investigational 21-valent pneumococcal conjugate vaccine.
- The main outcomes are antibody response rates and IgG concentrations against pneumococcal serotypes.
- The trial is currently authorised in the EU Clinical Trials Information System.
What is pneumococcal oligosaccharide serotype 18C?
Pneumococcal oligosaccharide serotype 18C conjugated to CRM197 is a bacterial sugar (oligosaccharide) from the capsule of Streptococcus pneumoniae serotype 18C, chemically linked to a carrier protein called CRM197. It is one of fifteen pneumococcal serotype components in Vaxneuvance, a pneumococcal polysaccharide conjugate vaccine (15-valent, adsorbed) authorised in the European Union. The marketing authorisation holder is Merck Sharp & Dohme B.V. In the clinical trial record, this substance appears as part of Vaxneuvance, which serves as the comparator arm.
How does it work?
Conjugate vaccines link a bacterial polysaccharide or oligosaccharide to a protein carrier such as CRM197. This linkage helps the immune system, including that of young infants, recognise the bacterial sugar and produce protective antibodies against the pneumococcal serotype. The trial measures the resulting antibody response as immunoglobulin G (IgG) concentrations and seroresponse rates.
Which conditions is it used or studied for?
- Pneumococcal immunisation — the trial studies vaccination against pneumococcal disease in healthy infants from approximately 2 months of age.
How is it given?
The substance is formulated as a suspension for injection and is given by intramuscular injection. In the trial, the Vaxneuvance pre-filled syringe contains 0.5 millilitres of the 15-valent pneumococcal conjugate vaccine. A paediatric formulation exists in the product records.
What do the clinical trials show?
One Phase 3 interventional trial, authorised in the EU Clinical Trials Information System, includes this substance as part of the comparator vaccine Vaxneuvance. The trial enrols 1,113 healthy infants from approximately 2 months of age. It compares the antibody response induced by an investigational 21-valent pneumococcal conjugate vaccine (PCV21) with that induced by Vaxneuvance (15vPCV).
The main outcomes are the seroresponse rate and IgG concentration for the shared serotypes between the two vaccines and for the six serotypes unique to PCV21, measured 30 days after the toddler dose. The study aims to show non-inferiority for the shared serotypes and superiority for the serotypes unique to PCV21.
What side effects are known?
The provided sources do not report side effects for this substance.