Reduction of Carriage and Transmission of Streptococcus pneumoniae: The Beneficial 'Side Effect' of Pneumococcal Conjugate Vaccine

摘要

In 2000, the 7-valent polysaccharide pneumococcal conjugate vaccine (PCV7) was recommended in the United States for routine use in all infants and children aged <2 years and in high-risk children aged =S4 years . Several controlled clinical trials have shown that the vaccine is highly efficacious in preventing invasive pneumococcal disease (IPD) in vaccinated children. The incidence of vaccine-type IPD among children aged <5 years decreased 94% from 1998 to 2003 and plateaued in 2002-2005 . Use of the vaccine also reduced the incidence of IPD among un-vaccinated populations. In fact, from 1998 to 2003, the incidence of vaccine-type IPD decreased up to 60% among persons agejd >5 years [2-4], and a statistically significant decrease of ~40% among infants tc young to be vaccinated was also found [ These data suggest a key role for indire effects of PCV7#