Data derived from Basse, Upper River Region studies.

Note: * Incidence per 100000 person-years. UUR, Upper River Region. CRR, Central River Region.†Person-years at risk in the placebo group is calculated from Enwere et al. (2006) in which there were 330 episodes of invasive bacterial infection in vaccine and placebo groups with overall incidence of 1009 per 100000 person-years [14]; 0.5× (330/1009×10−5) = 16501 person-years.‡The number of NTS isolates in the placebo group is calculated using the ratio of NTS incidence in placebo (300×10−5) versus vaccine (262×10−5) groups = 1.14 [14], and given 92 NTS isolates were detected in both groups. Thus, there were 49 NTS isolates in the placebo group (49/43 = 1.14 and 49+43 = 92).§The number of pneumococcal isolates in the placebo group is calculated using the incidence of IPD in placebo (453×10−5) versus vaccine (256×10−5) groups = 1.77 [14], and given 94 pneumococcal bloodstream isolates were detected in both groups. Thus, there were 60 pneumococcal isolates in the placebo group (60/34 = 1.77 and 60+34 = 94).∥NTS incidence calculated using age-specific incidence from Enwere et al., i.e. 2–5 mo: 408, 6–11 mo: 360, 12–17 mo: 334, 18–23 mo: 293, 24–29 mo: 42, 3–4 years: extrapolated as half the incidence among those 2 years of age, 42/2 = 21, **IPD incidence calculated from age-specific values [14], 2–5 mo: 363, 6–11 mo: 576, 12–17 mo: 526, 18–23 mo: 351, 24–29 mo: 339, 3–4 yrs: extrapolated as 339/2 = 170. Calculation of [14]: 0.71[(363/2)+(576/2)+(526/2)+(351/2)+339+170+170]/5 = 225.††authors' unpublished data.