Immunogenicity of the Booster Dose of Two MenC Vaccines

Inclusion Criteria:

* Healthy toddlers of both sexes
* Toddlers of 14 to 19 months of age (including the day that the toddler is 14 and the day before he is 19 months of age)
* Children previously vaccinated with two doses of polysaccharide meningococcal C vaccine conjugated to tetanus toxoid or three doses of polysaccharide meningococcal C conjugated to CRM197 before 7 month of age.
* Informed consent signed by one or both parents who are adequately informed about the study.

Exclusion Criteria:

* Toddlers with severe diseases or axilar temperature ≥ 38,0ºC at inclusion time
* Toddlers with severe chronic diseases
* Toddlers who have received any other vaccine within the last month or with a programmed vaccination within the 28 subsequent days after the administration of the vaccine of study.
* Toddlers with clinical or bacteriological diagnosis of previous meningococcal disease.
* Toddlers with hypersensitivity to any of the components of the vaccines to study or antibiotics used during the manufacturing process that could be present as non- detectable traces (streptomycin, neomycin, polymyxin B).
* Toddlers with personal history of convulsions.
* Toddlers with known bleeding disorder no controlled
* Toddlers with known congenital or acquired immunodeficiency
* Toddlers who are receiving or have been received any treatment that could change the immune response (administration of intravenous immunoglobulin, systemic corticosteroids or haemoderivates) within the 3 previous months.
* A toddler that under investigator opinion is probable to be lost during the follow-up
* A toddler that is currently included or is planned to be included in any other clinical trial.
* A toddler that under investigator opinion must not be included in the study due to other medical or social reasons.