In short
Pneumococcal polysaccharide serotype 4 is one of ten pneumococcal polysaccharide components contained in the authorised vaccine Synflorix, a pneumococcal polysaccharide conjugate vaccine (adsorbed). In the registered clinical trial, this substance appears as part of a fixed combination product investigated in a completed Phase 2 study involving 100 healthy toddlers for the prevention of pneumococcal infections.
Key points
- Pneumococcal polysaccharide serotype 4 is a component of the authorised vaccine Synflorix, a pneumococcal polysaccharide conjugate vaccine (adsorbed).
- The registered Phase 2 trial enrolled 100 healthy toddlers aged 11 to 15 months.
- The trial status is completed, and it studied a monovalent pneumococcal conjugate candidate.
- The primary outcomes measured local reactions, systemic events, and adverse events after a 2-dose series.
- Synflorix is given as a suspension for injection by intramuscular use, in a 0.5 ml dose.
- The marketing authorisation holder for Synflorix is GlaxoSmithKline Biologicals S.A.
What is pneumococcal polysaccharide serotype 4?
Pneumococcal polysaccharide serotype 4 is one of the active components of Synflorix, a pneumococcal polysaccharide conjugate vaccine (adsorbed) that is authorised as a medicine in the European Union. The full substance name is PNEUMOCOCCAL POLYSACCHARIDE SEROTYPE 4 CONJUGATED TO PROTEIN D (DERIVED FROM NON-TYPEABLE HAEMOPHILUS INFLUENZAE) CARRIER PROTEIN ADSORBED ON ALUMINIUM PHOSPHATE. In the registered trial, the substance appears as part of a fixed combination product containing ten pneumococcal polysaccharide serotypes. The marketing authorisation holder is GlaxoSmithKline Biologicals S.A.
How does pneumococcal polysaccharide serotype 4 work?
Pneumococcal polysaccharide serotype 4 is a polysaccharide from the surface of the bacterium Streptococcus pneumoniae, conjugated to a carrier protein called protein D, which is derived from non-typeable Haemophilus influenzae. Conjugating the polysaccharide to a carrier protein helps the immune system recognise and respond to the polysaccharide, which leads to the production of antibodies against this specific pneumococcal serotype. The substance is adsorbed on aluminium phosphate, which acts as an adjuvant to enhance the immune response.
Which conditions is it used or studied for?
- Pneumococcal infections — infections caused by the bacterium Streptococcus pneumoniae, which can lead to serious illnesses such as pneumonia, meningitis, and bloodstream infections. The registered trial studied this condition in healthy toddlers.
- Respiratory tract diseases — the substance is classified under the therapeutic area of respiratory tract diseases, as pneumococcal infections commonly affect the lungs and airways.
How is pneumococcal polysaccharide serotype 4 given?
Pneumococcal polysaccharide serotype 4 is given as a suspension for injection by intramuscular use. In the Synflorix vaccine, one dose of 0.5 ml contains 3 micrograms of pneumococcal polysaccharide serotype 4, adsorbed on aluminium phosphate and conjugated to protein D carrier protein. The vaccine is presented in pre-filled syringes or vials for intramuscular injection.
What do the clinical trials show?
One registered clinical trial investigated this substance as part of a combination product. The trial, identified as 2023-505154-18-00, was a Phase 2 safety and immunogenicity study of a monovalent pneumococcal conjugate candidate in healthy toddlers. The study enrolled 100 participants aged 11 to 15 months and was completed. The primary outcomes measured were prompt local reactions such as redness, swelling, and pain at the injection site; prompt systemic events including fever, decreased appetite, drowsiness, and irritability; and adverse events and serious adverse events. The trial aimed to describe the safety profile of the candidate when administered as a 2-dose series.
What side effects are known?
The registered trial measured local reactions at the injection site, including redness, swelling, and pain, as well as systemic events such as fever, decreased appetite, drowsiness, and irritability. The trial also recorded adverse events and serious adverse events to assess the safety profile of the vaccine candidate.