| abstract |
Invention describes producing a chemically well-defined pneumococcal polysaccharide (Pn-Ps) by partial hydrolysis of unpurified Pn-Ps preparation up to predetermined level saving Pn-Ps antigenic properties. Partially hydrolysed Pn-Ps is essentially pure and can be used for producing Pn-Ps immunogenic protein (PRO) conjugate (Pn-Ps-PRO). These Pn-Ps-PRO conjugates exhibit high immunogenic activity. They contain protein complex (OMPC) of outer membrane of Neisseria meningitidis b or its recombinant or purified sub-units, e.g. MIEP, or other immunogenically active proteins which are covalently linked to partially hydrolysed highly pure Pn-Ps intermediate product. The latter is isolated from the most widespread pneumococci. These compounds are useful for prevention of pneumococcal infections in mammals. The conjugates are of particular value to vaccine compositions for inducing anti-pneumococcal immunity in mammals. The most preferable target group can be persons with unfavourable B-cells activity, elder persons and infants till age of two years due to feasibility of these conjugates to cause T-cells reaction. Pn-Ps-OMPC and Pn-Ps-MIEP conjugates are produced in a process containing the following steps: isolation of Ps from capsules of Streptococcus pneumoniae (pneumococci, PN) in culture, partial hydrolysis or mechanical splitting of Pn-Ps, fractionating the said Pn-Ps for obtaining product with smaller molecule size, polydispertion and viscosity, and covalent binding Pn-Ps to OMPC or MIEP. |