Vaccine

1. A method of immunising a human host against disease caused by Streptococcus pneumoniae infection comprising administering to the host an immunoprotective dose of a multivalent immunogenic composition comprising S. pneumoniae capsular saccharide conjugates of serotypes 1, 4, 5, 6B, 7F, 9V, 14, 18C, 19A, 19F, 22F and 23F and a pharmaceutically acceptable excipient, wherein each of the serotypes 1, 4, 5, 6B, 7F, 9V, 14, 18C, 22F and 23F is conjugated to a carrier protein independently selected from the group consisting of tetanus toxoid (TT), diphtheria toxoid (DT), CRM-197, fragment C of TT, PhtD, PhtBE, or PhtDE fusions, detoxified pneumolysin and protein D, and wherein the 19A and 19F is each independently conjugated to diphtheria toxoid or CRM197, wherein 19A capsular saccharide is directly conjugated to the carrier protein.

2. The method of claim 1 , wherein the ratio of carrier protein to 19A saccharide is between 5:1 and 1:5, 4:1 and 1:1 or 3.5:1 and 2.5:1 (w/w).

3. The method of claim 1 , wherein the average size of the 19A saccharide is above 100 kDa.

4. The method of claim 1 , wherein the average size of the 19A saccharide is between 110 and 700 kDa.

5. The method of claim 1 , wherein the average size of the 19A saccharide is between 110-300, 120-200, 130-180, or 140-160 kDa.

6. The method of claim 1 , wherein the average size of the 22F saccharide is above 100 kDa.

7. The method of claim 1 , wherein the average size of the 22F saccharide is between 110 and 700 kDa, 110-300, 120-200, 130-180, or 150-170 kDa.

8. The method of claim 1 , wherein the multivalent immunogenic composition further comprises an adjuvant.

9. The method of claim 1 , wherein the disease caused by Streptococcus pneumoniae infection is pneumonia or invasive pneumococcal disease (IPD) of elderly humans, exacerbations of chronic obstructive pulmonary disease (COPD) of elderly humans, otitis media of infant humans, meningitis and/or bacteremia of infant humans, or pneumonia and/or conjunctivitis of infant humans.