Immunogenicity and Safety of Boostrix Polio Vaccine as a Booster Dose in 5 to 6-year-old Children.

This phase 3b study will compare the immunogenicity and reactogenicity of the dTpa-IPV vaccine to that of a DTPa-IPV vaccine when administered as a booster dose in healthy children 5-6 years of age who have received three primary vaccination doses of DTPa-based vaccine according to the "3-5-11" month schedule recommended in Italy.

In this study, MMRV vaccine will also be co-administered to all children.


Eligibility Criteria:
Inclusion Criteria:

* A male or female child of 5 and 6 years of age at the time of vaccination.
* Subjects who received a complete 3-dose vaccination with a DTPa-based combined vaccine according to a 3-5-11 month schedule in line with recommendations in Italy.
* Subjects who received a first dose of a live attenuated measles-mumps-rubella vaccine in the second year of life, in line with recommendations in Italy.
* Subjects who the investigator believes that their parents/guardians can and will comply with the requirements of the protocol should be enrolled in the study.
* Written informed consent obtained from the parent or guardian of the subject.
* Healthy subjects as established by medical history and clinical examination before entering into the study.

Exclusion Criteria:

* Use of any investigational or non-registered product other than the study vaccine(s) within 30 days preceding the first 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.
* 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 tetanus, diphtheria, pertussis and/or poliomyelitis since vaccination in the first two years of life.
* Previous measles, mumps, rubella and/or varicella second dose vaccination.
* Known history of diphtheria, tetanus, pertussis, poliomyelitis, measles, mumps, rubella and/or varicella disease.
* Known exposure to measles, mumps, rubella and/or varicella within 30 days prior to study start.
* Any confirmed or suspected immunosuppressive or immunodeficiency condition, based on medical history and physical examination.
* History of allergic disease or reactions likely to be exacerbated by any component of the vaccine.
* Administration of immunoglobulin and/or any blood products within the three months preceding vaccination or planned administration during the study period.
* Occurrence of transient thrombocytopenia or neurological complications following an earlier immunisation against diphtheria and/or tetanus.
* 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.
* Residence in the same household as a person high risk for varicella
* The following condition is temporary or self-limiting, and a subject may be vaccinated once the condition has resolved if no other exclusion criteria is met:

  * Current febrile illness or axillary temperature ≥ 38.5 ºC or other moderate to severe illness within 24 hours of study vaccine administration.