Immunogenicity and Safety Study of NBP606 in Healthy Toddlers

Inclusion Criteria: * Healthy infants who completed 3 doses of primary vaccination (NBP606\_PCVI\_III\_2013), available for follow-ups during the study period. * The LAR (Legally Authorized Representative) who understand the requirements of the study and voluntarily consent to participate in the study. Exclusion Criteria: * Administration of other vaccines, except the ones provided in this study, within 1month prior to booster study * Known hypersensitivity to any components of the pneumococcal vaccine * Any confirmed or suspected immunosuppressive or immunodeficient conditions * Coagulation disorder contraindicating IM(intramuscular) vaccination * Participation to another study