Changes in <i>Streptococcus pneumoniae</i> Serotypes in the Nasopharynx of Japanese Children after Inoculation with a Heptavalent Pneumococcal Conjugate Vaccine
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In this study, we prospectively investigated changes in <i>Streptococcus pneumoniae</i> serotypes among Japanese children after heptavalent pneumococcal conjugate vaccine (PCV7) inoculation. We acquired nasopharyngeal swabs from the children at each routine PCV7 inoculation and again at least 2 months after the last PCV7 inoculation. We defined 2 periods with regard to each culture: the inoculation period as “the period of pre- or incomplete vaccination” and post-inoculation as “the period of post- or completed vaccination.” The prevalence of vaccine-type (VT) pneumococci was significantly reduced from 9.5% in the inoculation-period cultures to 2.9% in the post-inoculation cultures (<i>P</i> < 0.01). There was no statistical difference in the prevalence of non-vaccine-type pneumococci between the inoculation-period and post-inoculation cultures (24.1% versus 23.4%). The protection of PCV7 against nasopharyngeal colonization was inferred from the decrease in VT carriage post-inoculation. The decrease in VT carriage may be conducive to reducing VT transmission within the study area.
- Japanese Journal of Infectious Diseases
Japanese Journal of Infectious Diseases 67(1), 40-43, 2014
National Institute of Infectious Diseases, Japanese Journal of Infectious Diseases Editorial Committee