Pneumococcus^{a} | Prevalence in 9-mo-old children ^{b} | OR (95% CI), P value^{c} | aOR^{d} (95% CI),P value | Prevalence in 16-mo-old children | OR (95% CI),P value | aOR (95% CI),P value | ||
---|---|---|---|---|---|---|---|---|

PCV7- unvaccinated ( n = 181) | PCV7- vaccinated ( n = 175) | PCV7- unvaccinated ( n = 193) | PCV7- vaccinated ( n = 164) | |||||

lytA | 150 (82.9) | 125 (71.4) | 0.52 (0.31–0.86),P = 0.01 | 0.45 (0.23–0.87),P = 0.01 | 157 (81) | 123 (75) | 0.68 (0.41–1.14),P = 0.147 | 0.55 (0.29–1.03),P = 0.06 |

VT serotypes | 112 (61.9) | 63 (36) | 0.35 (0.21–0.58),P < 0.001 | 0.37 (0.19–0.7),P = 0.002 | 100 (51.8) | 54 (32.9) | 0.44 (0.27–7.01),P < 0.001 | 0.41 (0.26–0.63),P = 0.007 |

NVT serotypes | 54 (33.7) | 70 (40) | 1.74 (1.08–2.82),P = 0.002 | 1.88 (1.02–3.48),P = 0.02 | 73 (37.8) | 102 (62.2) | 1.81 (1.12–2.93),P < 0.001 | 2.2 (1.18–4.1),P = 0.01 |

↵a

*Streptococcus pneumoniae*carrying the*lytA*gene or*S*.*pneumoniae*serotypes. PCV7 (7-valent pneumococcal conjugate vaccine) serotypes/serogroups (VT) include 4, 6A/B, 9A/L/N/V, 14, 18 A/B/C, 19B/F, and 23F. Nonvaccine serotypes/serogroups (NVT) are 1, 3, 5, 6 C/D, 7C, 10A, 11A/B/C/D/F, 12A/B/F, 13, 15 A/B/C/F, 16F, 17F, 19A, 20, 21, 23A/B, and 34/37/17A.↵b Prevalence of pneumococcal nasopharyngeal colonization in 9-month-old or 16-month-old children vaccinated or not vaccinated with PCV7. The number of children colonized with pneumococcus is shown. The percentage of children colonized is shown in parentheses.

↵c The odds ratio (OR), the 95% confidence interval (95% CI) for the odds ratio (shown in parentheses), followed by the

*P*value.↵d The adjusted odds ratio (aOR) for pneumococcal colonization was determined by multivariate logistic regression, controlling for race, smoking household contact, co-trimoxazole use, day care attendance, and mean age at the time of sample collection.