Immunogenicity and Safety of GSK Biologicals' Boostrix Polio Vaccine in 3 and 4-year-old Children

Inclusion Criteria

• Subjects who the investigator believes that their parent(s)/Legally Acceptable Representative(s) (LAR) can and will comply with the requirements of the protocol should be enrolled in the study.
• A male or female child of 3 or 4 years of age at the time of booster vaccination (up to, but excluding 5 years of age).
• Subjects who have received a complete three-dose primary vaccination with diphtheria-tetanus-acellular pertussis (DTPa) vaccine and inactivated poliovirus (IPV) vaccine in the first six months of life, in line with recommendations in the United Kingdom (UK).
• Subjects who received a first dose of a live attenuated measles-mumps-rubella vaccine within the second year of life, in line with recommendations in the UK.
• Written informed consent obtained from the parent(s)/LAR(s) of the subject at the time of enrolment.
• Healthy subjects as established by medical history and clinical examination before entering into the study.

Exclusion Criteria

• Child in care.
• Use of any investigational or non-registered product other than the study vaccine(s) within 30 days preceding the booster dose of study vaccine, or planned use during the study period.
• Chronic administration of immunosuppressants or other immune-modifying drugs within six months prior to the booster vaccine dose.
• Administration of a vaccine not foreseen by the study protocol within 30 days prior to vaccination, or planned administration during the study period, with the exception of inactivated influenza vaccine.
• 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.
• Previous booster vaccination against diphtheria, tetanus, pertussis, poliomyelitis since primary vaccination in the first year of life.
• Previous measles, mumps and/or rubella second dose vaccination.
• Evidence of previous or intercurrent diphtheria, tetanus, pertussis, poliomyelitis, measles, mumps and/or rubella disease.
• Known exposure to measles, mumps and/or rubella within 30 days prior to study start.
• Any confirmed or suspected immunosuppressive or immunodeficiency condition, based on medical history and physical examination.
• History of any reaction or hypersensitivity likely to be exacerbated by any component of the vaccine.
• Administration of immunoglobulin and/or any blood products within the three months preceding the booster dose or planned administration during the study period.
• Occurrence of transient thrombocytopenia or neurological complications following an earlier immunisation.
• Occurrence of any of the following adverse events after a previous administration of a DTP vaccine:
• Hypersensitivity reaction to any component of the vaccine;
• Encephalopathy of unknown aetiology occurring within 7 days following previous vaccination with pertussis-containing vaccine;
• Fever >= 40°C within 48 hours of vaccination, not due to another identifiable cause;
• Collapse or shock-like state within 48 hours of vaccination;
• Convulsions with or without fever, occurring within 3 days of vaccination.
• Acute disease and/or fever at the time of enrolment or within 24 hours of study vaccine administration.