Multivalent pneumococcal polysaccharide-protein conjugate composition
View Patent ↗An immunogenic composition having 13 distinct polysaccharide-protein conjugates and optionally, an aluminum-based adjuvant, is described. Each conjugate contains a capsular polysaccharide prepared from a different serotype of Streptococcus pneumoniae (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F and 23F) conjugated to a carrier protein. The immunogenic composition, formulated as a vaccine, increases coverage against pneumococcal disease in infants and young children globally, and provides coverage for serotypes 6A and 19A that is not dependent on the limitations of serogroup cross-protection. Also described is a method for making an immunogenic conjugate comprising Streptococcus pneumoniae serotype 3 polysaccharide covalently linked to a carrier protein, the method including periodic acid oxidation of the polysaccharide in the presence of bivalent cations.
1. A method for making an immunogenic conjugate comprising Streptococcus pneumoniae serotype 3 polysaccharide covalently linked to a carrier protein, the method comprising:
(a) reacting purified serotype 3 polysaccharide with a mild acid resulting in a hydrolyzed serotype 3 polysaccharide;
(b) reacting the hydrolyzed serotype 3 polysaccharide with an oxidizing agent in the presence of bivalent cations resulting in an activated serotype 3 polysaccharide;
(c) compounding the activated serotype 3 polysaccharide with a carrier protein;
(d) reacting the compounded, activated serotype 3 polysaccharide and carrier protein with a reducing agent resulting in a serotype 3 polysaccharide:carrier protein conjugate; and
(e) capping unreacted aldehydes in the serotype 3 polysaccharide:carrier protein conjugate resulting in an immunogenic conjugate comprising Streptococcus pneumoniae serotype 3 polysaccharide covalently linked to a carrier protein.
2. The method of claim 1 , further comprising purifying the activated serotype 3 polysaccharide prior to compounding with the carrier protein.
3. The method of claim 1 , further comprising co-lyophilizing the compounded, activated serotype 3 polysaccharide and carrier protein prior to reacting with the reducing agent.
4. The method of claim 1 , further comprising purifying the immunogenic conjugate.
5. The method of claim 1 , wherein the mild acid is acetic acid.
6. The method of claim 1 , wherein the oxidizing agent is periodic acid and the bivalent cations are Mg 2+ .
7. The method of claim 1 , wherein the carrier protein is CRM 197 .
8. The method of claim 1 , wherein the reducing agent is sodium cyanoborohydride.
9. The method of claim 1 , wherein capping unreacted aldehydes comprises reacting the serotype 3 polysaccharide:carrier protein conjugate with sodium borohydride.
10. A method for making an immunogenic conjugate comprising Streptococcus pneumoniae serotype 3 polysaccharide covalently linked to a carrier protein, the method comprising:
(a) reacting purified serotype 3 polysaccharide with acetic acid resulting in a hydrolyzed serotype 3 polysaccharide;
(b) reacting the hydrolyzed serotype 3 polysaccharide with periodic acid in the presence of MgCl 2 resulting in an activated serotype 3 polysaccharide;
(c) purifying the activated serotype 3 polysaccharide;
(d) compounding the activated serotype 3 polysaccharide with a carrier protein;
(e) co-lyophilizing the compounded, activated serotype 3 polysaccharide and carrier protein;
(f) reacting the co-lyophilized, activated serotype 3 polysaccharide and carrier protein with sodium cyanoborohydride resulting in a serotype 3 polysaccharide:carrier protein conjugate; and
(g) capping unreacted aldehydes in the serotype 3 polysaccharide:carrier protein conjugate with sodium borohydride resulting in an immunogenic conjugate comprising Streptococcus pneumoniae serotype 3 polysaccharide covalently linked to a carrier protein.
11. The method of claim 10 , further comprising purifying the immunogenic conjugate.
12. The method of claim 10 , wherein the carrier protein is CRM 197 .
13. A method for making an activated Streptococcus pneumoniae serotype 3 polysaccharide, the method comprising:
(a) reacting purified serotype 3 polysaccharide with a mild acid resulting in a hydrolyzed serotype 3 polysaccharide; and
(b) reacting the hydrolyzed serotype 3 polysaccharide with an oxidizing agent in the presence of bivalent cations resulting in an activated serotype 3 polysaccharide.
14. The method of claim 13 , further comprising purifying the activated serotype 3 polysaccharide following oxidation.
15. The method of claim 13 , wherein the mild acid is acetic acid.
16. The method of claim 13 , wherein the oxidizing agent is periodic acid and the bivalent cations are Mg 2+ .