Changes in the Nature and Severity of Invasive Pneumococcal Disease in Children, Before and After the 7-Valent and 13-Valent Pneumococcal Conjugate Vaccine Programs in Calgary, Canada

Background:Since the introduction of childhood pneumococcal conjugate vaccines, invasive pneumococcal disease (IPD) incidence has decreased in children and the predominant serotypes causing disease have changed. This study describes changes in the clinical features of IPD in children (<18 years) bef