Affiliation:
1. Department of Medical Microbiology and Infectious Diseases, Max Rady College of Medicine , Room 543-745 Bannatyne Avenue, Winnipeg, Manitoba R3E 0J9 , Canada
2. Clinical Microbiology, Shared Health , MS673-820 Sherbrook Street, Winnipeg, Manitoba R3A 1R9 , Canada
3. National Microbiology Laboratory, Public Health Agency of Canada , 1015 Arlington Street, Winnipeg, Manitoba R3E 3R2 , Canada
Abstract
Abstract
Background
As pneumococci evolve under vaccine, antimicrobial and other selective pressures, it is important to track isolates covered by established (PCV10, PCV13 and PPSV23) and new (PCV15 and PCV20) vaccine formulations.
Objectives
To compare invasive pneumococcal disease (IPD) isolates from serotypes covered by PCV10, PCV13, PCV15, PCV20 and PPSV23, collected in Canada from 2011 to 2020, by demographic category and antimicrobial resistance phenotype.
Methods
IPD isolates from the SAVE study were initially collected by members of the Canadian Public Health Laboratory Network (CPHLN) as part of a collaboration between the Canadian Antimicrobial Resistance Alliance (CARA) and the Public Health Agency of Canada (PHAC). Serotypes were determined by quellung reaction, and antimicrobial susceptibility testing was performed using the CLSI broth microdilution method.
Results
A total of 14 138 invasive isolates were collected from 2011 to 2020, with 30.7% of isolates covered by the PCV13 vaccine, 43.6% of isolates covered by the PCV15 vaccine (including 12.9% non-PCV13 serotypes 22F and 33F), and 62.6% of isolates covered by the PCV20 vaccine (including 19.0% non-PCV15 serotypes 8, 10A, 11A, 12F and 15B/C). Non-PCV20 serotypes 2, 9N, 17F and 20, but not 6A (present in PPSV23) represented 8.8% of all IPD isolates. Higher-valency vaccine formulations covered significantly more isolates by age, sex, region and resistance phenotype including MDR isolates. Coverage of XDR isolates did not significantly differ between vaccine formulations.
Conclusions
When compared with PCV13 and PCV15, PCV20 covered significantly more IPD isolates stratified by patient age, region, sex, individual antimicrobial resistance phenotypes and MDR phenotype.
Funder
University of Manitoba
Public Health Agency of Canada
Pfizer Canada
Merck
Publisher
Oxford University Press (OUP)
Subject
Infectious Diseases,Pharmacology (medical),Pharmacology,Microbiology (medical)