Changing Epidemiology of Invasive Pneumococcal Disease in Canada, 1998–2007: Update from the Calgary‐Area<i>Streptococcus pneumoniae</i>Research (CASPER) Study

Abstract

Since the introduction of PCV7 vaccine, there has been a profound decrease in the total number of cases of IPD among children and in cases due to PCV7 serotypes among subjects of all ages in Calgary, indicating a strong direct effect and herd effect of the vaccine. The serotypes that now cause IPD have changed significantly. The magnitude and impact of replacement IPD caused by non-PCV7 serotypes is not yet known.