Process for the production of immunogenic compositions

1. A process for the production of an immunogenic polypeptide comprising the steps of:

(i) treating a polypeptide consisting of SEQ ID NO:2 to reduce a disulfide bond and produce a free thiol group;

(ii) blocking said free thiol group with a blocking agent;

(iii) purifying a polypeptide resulting from step (ii) using one or more chromatographic purification steps,

where the purified polypeptide is immunogenic and contains said blocking agent.

2. The process of claim 1 , wherein said blocking agent is iodoacetamide.

3. The process of claim 1 , wherein the purified polypeptide is carboxyamidated.

4. The process of claim 1 , wherein the purified polypeptide is carboxymethylated.

5. The process of claim 1 , wherein the purified polypeptide is lipidated.

6. The process of claim 1 , further comprising formulating the purified polypeptide as a pharmaceutical composition.

7. A process for the production of an immunogenic composition comprising the steps of:

(i) treating a polypeptide consisting of SEQ ID NO:2 to reduce a disulfide bond and produce a free thiol group;

(ii) blocking said free thiol group with a blocking agent;

(iii) purifying a polypeptide resulting from step (ii) using one or more chromatographic purification steps, where the purified polypeptide is immunogenic and contains said blocking agent; and

(iv) formulating the purified polypeptide as a pharmaceutical composition.

8. The process of claim 7 , wherein said blocking agent is iodoacetamide.

9. The process of claim 7 , wherein the purified polypeptide is carboxyamidated.

10. The process of claim 7 , wherein the purified polypeptide is carboxymethylated.

11. The process of claim 7 , wherein the purified polypeptide is lipidated.

12. The process of claim 6 , where said pharmaceutical composition comprises a pharmaceutically acceptable excipient.