Disease in the Era of Conjugate

Background. Changes in invasive pneumococcal disease (IPD) incidence were evaluated after 7 years of 7-valent pneumococcal conjugate vaccine (PCV7) use in US children. Methods. Laboratory-confirmed IPD cases were identified during 1998–2007 by 8 active population-based surveillance sites. We compared overall, age group–specific, syndrome-specific, and serotype group–specific IPD incidence in 2007 with that in 1998–1999 (before PCV7) and assessed potential serotype coverage of new conjugate vaccine formulations. Results. Overall and PCV7-type IPD incidence declined by 45 % (from 24.4 to 13.5 cases per 100,000 popu-lation) and 94 % (from 15.5 to 1.0 cases per 100,000 population), respectively ( for all age groups). TheP!.01 incidence of IPD caused by serotype 19A and other non-PCV7 types increased from 0.8 to 2.7 cases per 100,000 population and from 6.1 to 7.9 cases per 100,000 population, respectively ( for all age groups). The ratesP!.01 of meningitis and invasive pneumonia caused by non-PCV7 types increased for all age groups (), whereasP!.05 the rates of primary bacteremia caused by these serotypes did not change. In 2006–2007, PCV7 types caused 2