Only the Alaska Native and Australian Aboriginal populations had high (≥50%) pre-introduction VT carriage (Appendix B.3, Table 5; data from older children and teenagers). Therefore, it remains unclear whether the relationship between impact on NP carriage relative see more to that for VT-IPD varies with preexisting carriage burden. Primary evidence included 38 articles representing 9 countries and 26 populations (some overlapping), including indigenous populations, HIV and AIDS patients, and the general population. PCV introduction was nearly invariably followed

by sharp reductions in VT-IPD rates in non-targeted populations, including infants too young to be immunized [36] (Appendix B.3, Table 1). The median proportion decrease in VT-IPD incidence among unimmunized age-groups increased with number of years post routine PCV introduction (Table 2). Of 56 age-specific data points, 53 reported decreases in VT-IPD incidence. All age-groups experienced significant indirect benefit, with many data points showing declines in VT-IPD below 50% and near elimination for those with the longest

follow-up (Fig. 4). Median percentage decrease in VT-IPD was 57% (interquartile range [IQR]: 40–77%) for the general population, 67% (IQR: 40–85%) for aboriginal populations, and 30% (IQR: 13–46%) for HIV-positive populations (data not shown). Plateaus in values should not be interpreted to mean that Selleckchem GSKJ4 within a population this plateau is observed since values reflect data from varying settings and countries. PCV vaccination coverage among targeted age-groups was reported in heterogeneous formats across the various publications, limiting summary correlations between VT-IPD changes among non-targeted age-groups and coverage (Table 3) although these seemed to correlate over time. When coverage rates were high, evidence for indirect impact was consistent; it was mixed with low coverage rates but suggestive, starting at 3-dose coverage among 19–35-month-olds as low as 40%. If PCV target-aged children were the only significant pneumococcal carriers in communities, rates of

VT-IPD in all age-groups might fall proportionate to some function of coverage soon after introduction. Instead, decreases in VT-IPD in non-target groups exceed contemporaneous 3-dose vaccine coverage rates in their communities (Table Ketanserin 3). In the US ABCs and Navajo populations where vaccine has been used the longest albeit with imperfect coverage, VT-IPD among non-target groups has been virtually eliminated in the 5–10 years following introduction. Six data sets (all from Australia) evaluated a primary series schedule without a PCV booster dose; the median decrease of VT-IPD among non-target groups was 60% (IQR: 50–67%). The median decrease in VT-IPD in countries using a PCV booster dose was 62% (IQR: 40–78%) [37], [38], [39], [40], [41], [42], [43], [44] and [45]. Appendix B.4 includes a full discussion of supporting data.