Pneumococcal polysaccharides and their use in immunogenic polysaccharide-carrier protein conjugates
The present invention provides capsular polysaccharides from Streptococcus pneumoniae serotypes identified using NMR. The present invention further provides polysaccharide-protein conjugates in which capsular polysaccharides from one or more of these serotypes are conjugated to a carrier protein such as CRM197. Polysaccharide-protein conjugates from one or more of these serotypes may be included in multivalent pneumococcal conjugate vaccines having polysaccharides from multiple additional Steptococcus pneumoniae serotypes.
1. A method of inducing an immune response to a Streptococcus pneumoniae capsular polysaccharide, comprising administering to a human an immunologically effective amount of an immunogenic composition comprising a polysaccharide-carrier protein conjugate and a pharmaceutically acceptable carrier, wherein the polysaccharide of the polysaccharide-carrier protein conjugate comprises a repeating unit of the following structure:
wherein each x independently indicates a molar ratio from 0 to 1.0; wherein the carrier protein is CRM197; wherein the polysaccharide-carrier protein conjugate has a molecular weight from 1,000 kDa to 10,000 kDa; and further wherein the polysaccharide-carrier protein conjugate has a polysaccharide to carrier protein mass ratio from 0.5 to 2.0.
2. The method of claim 1 , wherein the immunogenic composition further comprises one or more additional polysaccharide-carrier protein conjugates, wherein each of the conjugates comprises a polysaccharide of a particular S. pneumoniae serotype conjugated to CRM197, and wherein the S. pneumoniae serotypes are selected from the group consisting of: 1, 2, 3, 4, 5, 6A, 6B, 6C, 6D, 7B, 7C, 7F, 8, 9N, 9V, 10A, 11A, 12F, 14, 15A, 15B, 15C, 17F, 18C, 19A, 19F, 20, 21, 22A, 22F, 23A, 23B, 23F, 24F, 27, 28A, 31, 33F, 34, 35A, 35B, 35F, and 38.
3. The method of claim 2 , wherein the immunogenic composition is formulated to comprise: 0.4 to 4 μg/mL of each polysaccharide present, except for serotype 6B polysaccharide which, if present, comprises 0.8 to 8 μg/mL of polysaccharide; and CRM197 carrier protein in an amount from about 0.5× to 3× the total amount of polysaccharide.
4. The method of claim 3 , wherein the immunogenic composition is formulated to further comprise 150 mM sodium chloride, 20 mM L-histidine buffer, and 0.05 to 2% w/v surfactant.
5. The method of claim 4 , wherein the immunogenic composition further comprises an adjuvant.
6. The method of claim 5 , wherein the adjuvant is an aluminum-based adjuvant.
7. The method of claim 6 , wherein the adjuvant is selected from the group consisting of aluminum phosphate, aluminum sulfate, and aluminum hydroxide.
8. The method of claim 7 , wherein the adjuvant is aluminum phosphate.
9. The method of claim 8 , wherein the aluminum phosphate adjuvant is present at a concentration from 0.05 to 0.5 mg/mL.
10. The method of claim 1 , wherein x is from 0.5 to 1.0.
11. The method of claim 1 , wherein x is from 0.7 to 1.0.
12. The method of claim 1 , wherein the carrier protein is conjugated to the polysaccharide through the carbon 2 position of a glycerol-1-PO 4 sugar.
13. The method of claim 1 , wherein the degree of conjugation of the conjugate is between 3-13.
14. The method of claim 1 , wherein the polysaccharide has a molecular weight of between 50 kDa and 1,000 kDa.
15. The method of claim 1 , wherein the polysaccharide has a molecular weight of between 100 kDa and 300 kDa.
16. The method of claim 1 , wherein the polysaccharide-carrier protein conjugate has a polysaccharide to carrier protein mass ratio from 0.5 to 1.5.
17. The method of claim 1 , wherein the polysaccharide-carrier protein conjugate has a polysaccharide to carrier protein mass ratio from 0.8 to 1.2.
18. The method of claim 1 , wherein the immunogenic composition comprises less than about 25% of non-covalently associated polysaccharide compared to the total amount of polysaccharide.
19. The method of claim 1 , wherein the immunogenic composition comprises less than about 15% of non-covalently associated polysaccharide compared to the total amount of polysaccharide.
20. The method of claim 1 , wherein x is from 0.7 to 1.0; wherein the carrier protein is conjugated to the polysaccharide through the carbon 2 position of a glycerol-1-PO 4 sugar; wherein the degree of conjugation of the conjugate is between 3-13; wherein the polysaccharide has a molecular weight of between 100 and 300 kDa; wherein the mass ratio of polysaccharide to carrier protein in the conjugate is between 0.5 and 1.5; and wherein the polysaccharide-carrier protein conjugate comprises less than about 15% of non-covalently associated polysaccharide compared to the total amount of polysaccharide.
21. The method of claim 2 , wherein the immunogenic composition is a single 0.5 mL dose formulated to comprise: 2 μg of each polysaccharide present, except for serotype 6B polysaccharide which, if present, is 4 μg; about 32 μg CRM197 carrier protein; 0.125 mg aluminum phosphate adjuvant; 150 mM sodium chloride, 20 mM L-histidine buffer, and 0.2% w/v PS-20.