Immunological persistence after priming with GSK1024850A vaccine and safety& immunogenicity after booster dose

Subjects who the investigator believes that their parent(s)/Legally Acceptable Representative(s) (LAR) can and will comply with the requirements of the protocol

• Male or female between, and including, 18 and 21 months of age at the time of booster vaccination.
• Subjects who received three doses of pneumococcal conjugate vaccine in study NCT00808444
• Written informed consent obtained from the parents/LAR(s) of the subject.
• Healthy subjects as established by medical history and clinical examination before entering into the study.

Use of any investigational or non-registered product other than the study vaccine(s) within 30 days preceding vaccination, or planned use during the study period.

• Concurrently participating in another clinical study, at any time during the study period, in which the subject has been or will be exposed to an investigational or a non-investigational product.
• Chronic administration of immunosuppressants or other immune-modifying drugs within six months prior to vaccination.
• A family history of congenital or hereditary immunodeficiency.
• Administration of immunoglobulins and/ or any blood products within the 3 months preceding vaccination or planned use during the study period.
• Administration of any pneumococcal and/or vaccine containing diphtheria, tetanus, pertussis, poliomyelitis or Haemophilus influenzae type b antigens since the end of study NCT00808444.
• Planned administration/administration of a vaccine not foreseen by the study protocol during the study period starting from 30 days before vaccination and ending 30 days after vaccination.
• Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination (no laboratory testing required).
• History of any reaction or allergic disease likely to be exacerbated by any component of the study vaccines.
• Known hypersensitivity to any component of the study vaccines including anaphylactic reactions following the administration of the study vaccines.
• Major congenital defects or serious chronic illness.
• History of any neurologic disorders or seizures. (Subjects who have had a single uncomplicated febrile convulsion in the past can be included)
• Fever at the time of vaccination. -Fever is defined as rectal temperature >= 38.0°C or tympanic/axillary/ oral temperature >= 37.5°C.
• Acute disease at the time of enrolment.

Subjects with a minor illness without fever may be enrolled at the discretion of the investigator.

• Child in care.