Nasopharyngeal Carriage Study in Healthy Kenyan Toddlers

Inclusion Criteria: \- For Toddlers Enrolled in VAC-010 (NCT02097472): * Randomization in VAC-010. * Subject's parent must provide voluntary written informed consent for subject to participate in the study, is fully capable of comprehending and complying with study requirements and procedures, able and willing to return for all scheduled follow-up visits, and has expressed availability for the required study period, with access to a consistent means of telephone contact. An illiterate parent will require an impartial witness to be present during consenting process to include discussing the consent form, verbal consent and thumb-printing. * Subject has not completed his or her final vaccination in VAC-010. For Toddlers NOT Enrolled in VAC-010 (PCV-primed-only cohort): * Healthy Kenyan toddlers between 12 to 15 (inclusive) months of age who have completed their primary Expanded Programme on Immunization (EPI) vaccines, with the exception that the birth dose of oral polio vaccine is not required. * Subjects who have not received a PCV booster following primary PCV series. * Subject's parent must provide voluntary written informed consent for subject to participate in the study, is fully capable of comprehending and complying with study requirements and procedures, able and willing to return for all scheduled follow-up visits, and has expressed availability for the required study period, with access to a consistent means of telephone contact. An illiterate parent will require…