Opsonophagocytic indices of serotype 14 (PMP829, STREP14), nonencapsulated (PMP1474) and 14-like (PMP1437, PMP1438, and PMP1514) pneumococci. Isolates were incubated with either 007SP reference sera (red triangles) or sera from individuals vaccinated with PCV7 and/or PPSV23. Each symbol represents an individual serum sample with black, gray, and white colors representing serum samples with high (>10 μg/mL), medium (1 to 5 μg/mL), and low (<0.5 μg/mL) serotype 14 IgG titers, respectively. Times specified in brackets below are the ages of the children at the time of vaccination. Red triangle, 007SP reference sera; black circle, 1 dose PCV7 (2 years); black square, 1 dose PPSV23 (12 months) + 1 dose PCV7 (2 years); gray circle, 1 dose PCV7 (2 years); gray square, 2 doses PCV7 (14 weeks and 2 years); white square, 2 doses PCV7 (6 and 14 weeks) + 1 dose PPSV23 (12 months). OI 4 (dotted line) or less is defined as negative for opsonophagocytic killing. Nonspecific killing in this assay was −25%, −12%, −2%, 21%, 2%, and 20% for PMP829, STREP14, PMP1474, PMP1437, PMP1438, and PMP1514, respectively.