Evaluate Pathogens and Immunity to Acute Otitis Media in Healthy Children.

Inclusion Criteria: Healthy Children: * Male or female age greater than/equal to 6 months or less than/equal to 36 months old. * Parent/guardian willing to bring to all study visits Exclusion Criteria: * Any major illness/condition that in investigator opinion would put subject at risk during study. * Otorrhea or tympanostomy tubes present in either ear @ time of enrollment. * Direct descendant of study site personnel. * Subjects \< 6 months old or \>36 months old at the time of enrollment