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Category: Bacterial Pathogenesis; Immunology
Pneumococcal Serotype Epidemiology, Page 1 of 2
< Previous page | Next page > /docserver/preview/fulltext/10.1128/9781555815820/9781555814083_Chap10-1.gif /docserver/preview/fulltext/10.1128/9781555815820/9781555814083_Chap10-2.gifAbstract:
This chapter summarizes the relative prevalences of the most common serotypes prior to and following the introduction of the heptavalent pneumococcal capsular polysaccharide vaccine (PCV-7). It provides thoughts about the selection of serotypes for future-generation conjugate vaccines. A remarkable feature of the global epidemiology of pneumococcal carriage is the consistency of the dominant carriage serotypes in very different environments and at different times. Invasive disease potential, or invasiveness, is a measure of the ability of pneumococci to progress from nasopharyngeal carriage to invasive disease in humans. It differs from virulence in that the latter is often used to describe the ability of a pathogen to cause disease in laboratory animals. The 11-valent formulation prevented vaccine-related otitis media and was also shown to elicit antibodies with functional immunogenicity (opsonophagocytic activity) against 6A comparable to that seen with PCV-7. The incidence of invasive pneumococcal disease (IPD) due to vaccine serotypes has decreased substantially since the introduction of PCV-7 in the United States, in vaccinated children as well as all other age groups, indicating that pneumococcal transmission was interrupted as a result of the reduction in carriage in the vaccinated pediatric population. For mucosal disease, otitis media and nonbacteremic pneumonia, it is less clear which serotypes it would be most valuable to add since there appear to be less clearcut differences in invasiveness among serotypes. The only certain way of preventing mucosal disease is to sterilize the nasopharynx with respect to pneumococci.
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Percentages of IPD isolates represented in the PCV-7 formulation and recovered from children <5 years of age. As indicated in the figure, shading refers to the percentages of all IPD isolates identified as serotypes 4, 6A, 6B, 9V, 14, 18C, 19F, and 23F. Data sources are references cited in reference 79 and references 3 , 4 , 6 , 11 – 12 , 16 , 17 , 23 , 25 – 29 , 31 – 37 , 42 , 44 , 49 , 60 , 65 , 67 , 70 , 86 , 87 , 91 , 94 , 96 – 98 , 100 , 102 , 103 , 105 – 107 , 109 – 111 , 113 , 115 , 117 , 123 , 124 , 132 , 134 – 136 , 138 , 142 , 143 , 153 , 154 , 156 , 158 – 162 , 164 , 167 – 169 , 172 , 174 , 177 – 179 , 188 – 190 , 195 – 200 , 202 , 203 , 208 .
Percentages of IPD isolates represented in the PHiD CV-10 formulation and recovered from children <5 years of age. As indicated in the figure, shading refers to the percentages of all IPD isolates identified as serotypes 1, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19F, and 23F. Countries marked with two shades correspond to percentage of serotype coverage exactly intermediate between the percentages represented by the two shades. Data sources are those cited in the legend to Fig. 1 .
Percentages of IPD isolates represented in the PCV-7 formulation and recovered from children <5 years of age. As indicated in the figure, shading refers to the percentages of all IPD isolates identified as serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F. Data sources are those cited in the legend to Fig. 1 .