The seven-valent pneumococcal conjugate vaccine (PCV7) was licensed in Canada in 2001. Routine infant vaccination programs in Alberta began in 2002. Several years after PCV7 introduction, the routine use of PCV7 in infants and high-risk children has led to near elimination of invasive pneumococcal disease (IPD) caused by vaccine serotypes.
Prospective, population-based surveillance of all IPD cases was conducted from January 1998 to December 2010. Demographic, clinical and microbiologic data were collected.
There were 1462 IPD cases over 13 years. Comparing PCV7 serotype IPD incidence in the prevaccine period (1998–2001) to the late postvaccine period (2007–2010), there were declines in children 0–5 months (100%), 6–23 months (98%), 2–4 years (97%), 5–15 years (100%) as well as in adults 16–64 years (73%), 65–84 years (90%) and ≥85 years of age (100%). From 2008 to 2010, there were no cases of PCV7 serotype IPD in children under 2 years of age. There have been increases in non-PCV7 serotype IPD; notably, serotypes 5 and 19A have increased significantly in adults and 19A in children.
PCV7 serotype IPD has been eliminated in vaccine-eligible young children and nearly eliminated in all other age groups. Serotype 19A increased significantly at all ages before the introduction of an expanded valency pneumococcal conjugate vaccine.
From the *Departments of Pediatrics, †Microbiology, Immunology and Infectious Diseases, and ‡Pathology and Laboratory Medicine, University of Calgary; §Department of Medicine, University of Calgary; ¶Calgary Laboratory Services; ║Population and Public Health, Alberta Health Services; **Department of Community Health Sciences, University of Calgary, Calgary; ††National Centre for Streptococcus, Edmonton; and the ‡‡Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada.
Accepted for publication, May 31, 2012.
OGV, JM and JDK are supported by an Investigator Initiated Research Grant from Pfizer Canada Inc. The authors have no other funding or conflicts of interest to disclose.
Address for Correspondence: Otto G. Vanderkooi, MD, Division of Infectious Diseases, Alberta Children’s Hospital, 2888 Shaganappi Trail NW Calgary, AB T3B 6A8, Canada. E-mail: firstname.lastname@example.org.