Multivalent ExPEC Vaccine Composition with Elevated O75 Antigen
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Solution Overview
Problem
The development of an effective vaccine against extraintestinal pathogenic Escherichia coli (ExPEC) is challenging due to the antigenic diversity and immunogenicity issues of O-antigens, particularly the E. coli O75 serotype, which is less immunogenic when conjugated with other O-antigens, and the prevalence of multi-drug resistant strains like ST131.
Innovation Solution
A multivalent vaccine composition comprising E. coli O1, O2, O4, O15, O16, O18, O25, and O75 antigen polysaccharides, with O75 antigen polysaccharide concentrations increased relative to other antigens, covalently linked to a carrier protein, to enhance immune response against ExPEC.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If E. coli O75 antigen polysaccharide is conjugated with other O-antigens at the same concentration, then the vaccine composition is simpler to formulate, but the immune response against O75 serotype is insufficient due to lower immunogenicity
Solution Approach 1:
The patent applies local quality by assigning different concentrations to different antigen polysaccharides within the same vaccine composition. Specifically, E. coli O75 antigen polysaccharide is included at a higher concentration (10-50 μg per dose) compared to other O-antigens (5-20 μg per dose) to compensate for its lower immunogenicity, while maintaining the overall multivalent formulation structure
Solution Approach 2:
The patent changes the concentration parameter of E. coli O75 antigen polysaccharide from the standard equal-distribution approach to a specifically elevated level (10-50 μg per dose versus 5-20 μg for others). This parameter adjustment ensures adequate immune response against the less immunogenic O75 serotype while maintaining feasibility of vaccine formulation
2Reliability
If E. coli O75 antigen polysaccharide concentration is increased relative to other antigens, then the immune response against O75 serotype is enhanced, but the vaccine manufacturing precision becomes more challenging
Solution Approach 1:
The patent defines specific concentration ranges for E. coli O75 antigen polysaccharide (10-50 μg per dose) and other O-antigens (5-20 μg per dose), providing clear manufacturing parameters that balance immune response enhancement with production feasibility. These parameter specifications enable controlled manufacturing while achieving the desired immunogenicity profile
3Adaptability or versatility
If a multivalent vaccine includes multiple O-antigens, then the coverage against diverse ExPEC serotypes is improved, but the antigenic diversity makes it difficult to achieve effective immunization against all serotypes
Solution Approach 1:
The patent applies local quality by selecting specific O-antigens (O1, O2, O4, O15, O16, O18, O25, O75) that represent predominant ExPEC serotypes and assigning them differentiated concentrations. This approach provides targeted coverage against major serotypes while using higher concentration for the less immunogenic O75 to ensure effective immunization
Solution Approach 2:
The patent creates a composite vaccine composition combining multiple O-antigen polysaccharides with different concentrations. This composite formulation leverages the protective effects of multiple serotypes while using optimized concentration ratios to overcome individual antigen limitations, particularly the lower immunogenicity of O75
Data Source
AI summary
Compositions and methods are described for inducing an immune response against extra-intestinal pathogenic Escherichia coli (ExPEC) to thereby provide immune protection against diseases associated with ExPEC. In particular, compositions and methods are described for using conjugates of E. coli polysaccharide antigen O75 covalently bound to a carrier protein for the prevention of invasive ExPEC disease.