Capsular polysaccharide solubilisation and combination vaccines

Patent metadata

Field	Value
Publication number	US-9782467-B2
Application number	US-32143409-A
Country	US
Kind code	B2
Filing date	Jan 20, 2009
Priority date	Jun 20, 2001
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

Precipitated bacterial capsular polysaccharides can be efficiently re-solubilized using alcohols as solvents. The invention provides a process for purifying a bacterial capsular polysaccharide, comprising the steps of (a) precipitation of said polysaccharide, followed by (b) solubilization of the precipitated polysaccharide using ethanol. CTAB can be used for step (a). The material obtained, preferably following hydrolysis and sizing, can be conjugated to a carrier protein and formulated as a vaccine. Also, in vaccines comprising saccharides from both serogroups A and C, the invention provides that the ratio (w/w) of MenA saccharide:MenC saccharide is >1.

First claim

The invention claimed is:

1. A process for conjugating a bacterial capsular saccharide to a carrier protein, comprising:
purifying the saccharide, comprising the steps of (a) precipitation of the saccharide using one or more cationic detergents, followed by (b) solubilisation of the precipitated saccharide using an alcohol, then (c) precipitating the saccharide obtained in step (b) by exchanging cations,
conjugating the saccharide to a carrier protein, wherein the carrier protein is a bacterial toxin or toxoid, and wherein conjugation is with a linker, and
mixing the conjugated saccharide with a second bacterial capsular saccharide conjugated to a second carrier protein, wherein the second carrier protein is the bacterial toxin or toxoid,

wherein the bacterial capsular saccharide is from Neisseria meningitidis serogroup A, W135 or Y, or from Haemophilus influenzae , or from Streptococcus pneumoniae.

2. The process of claim 1 , wherein the cationic detergent(s) comprise a cetyltrimethylammonium salt, a tetrabutylammonium salt, a myristyltrimethylammonium salt and/or hexadimethrine bromide.

3. The process of claim 1 or claim 2 , wherein the alcohol used in step (b) comprises ethanol, and wherein the ethanol has a final concentration of between 50% and 95%.

4. The process of claim 1 , wherein the precipitation in step (c) is by addition of calcium or sodium salts.

5. The process of claim 1 , wherein the saccharide is activated prior to conjugation.

6. The process of claim 5 , wherein activation involves a cyanylating reagent.

7. The process of claim 1 , wherein the conjugated saccharide has a saccharide:protein ratio (w/w) between 0.5:1 and 5:1.

8. The process of claim 5 , wherein the conjugated saccharide has a saccharide:protein ratio (w/w) between 0.5:1 and 5:1.

9. The process of claim 1 , wherein the carrier protein is diphtheria toxoid or tetanus toxoid.

10. The process of claim 5 , wherein the carrier protein is diphtheria toxoid or tetanus toxoid.

11. The process of claim 1 , wherein, after conjugation, free and conjugated saccharides are separated.

12. The process of claim 5 , wherein, after conjugation, free and conjugated saccharides are separated.

13. The process of claim 11 , wherein separation uses hydrophobic chromatography, tangential ultrafiltration, or diafiltration.

14. The process of claim 1 , wherein the step of mixing the conjugated saccharide with the second bacterial capsular saccharide conjugated to a second carrier protein gives a mixture of saccharides from more than one serogroup of N. meningitidis.

15. The process of claim 14 , wherein saccharide antigens from N. meningitidis strains A, C, W 135 and/or Y are mixed.

16. The process of claim 15 , wherein mixing gives a composition comprising capsular saccharides from both serogroups A and C and the ratio (w/w) of MenA saccharide:MenC saccharide is 2:1.

17. The process of claim 15 , wherein mixing gives a composition comprising capsular saccharides from serogroup Y and one or both of serogroups C and W135, and wherein the ratio (w/w) of MenY saccharide:MenW135 saccharide is greater than 1 and/or that the ratio (w/w) of MenY saccharide:MenC saccharide is less than 1.

Assignees

• Costantino Paolo
• Glaxosmithkline Biologicals Sa

Inventors

• Costantino Paolo

Classifications

• A61P37/02

  Immunomodulators · CPC title

• A61P31/04

  Antibacterial agents · CPC title

• A61P43/00

  Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00 · CPC title

• A61P37/04

  Immunostimulants · CPC title

• C07H15/04

  attached to an oxygen atom of the saccharide radical · CPC title