POPULATION EFFECTS OF PNEUMOCOCCAL CONJUGATE VACCINES ON INVASIVE PNEUMOCOCCAL DISEASE IN CANADA — A TARGETED LITERATURE REVIEW
Author(s)
Min Huang, PhD1, Jipan Xie, MD, PhD2, Weiguang Xue, MSc3, Yanwen Xie, MS4, Walter A. Orenstein, MD5, Elamin Elbasha, BSc, MA, PhD6, Matthew S. Kelly, MD, MPH7;
1Merck & Co. Inc, Sr. Principal Scientist, North Wales, PA, USA, 2XL Source, Inc., Los Angeles, CA, USA, 3Analysis Group, London, United Kingdom, 4Analysis Group, Inc., Los Angeles, CA, USA, 5Emory University, School of Medicine, Atlanta, GA, USA, 6Merck & Co. Inc, West Point, PA, USA, 7Arkansas Children’s Hospital, Little Rock, AR, USA
1Merck & Co. Inc, Sr. Principal Scientist, North Wales, PA, USA, 2XL Source, Inc., Los Angeles, CA, USA, 3Analysis Group, London, United Kingdom, 4Analysis Group, Inc., Los Angeles, CA, USA, 5Emory University, School of Medicine, Atlanta, GA, USA, 6Merck & Co. Inc, West Point, PA, USA, 7Arkansas Children’s Hospital, Little Rock, AR, USA
OBJECTIVES: PCV7 (7‑valent pneumococcal conjugate vaccine) was introduced in infants in Canada in 2002-2003 and replaced by PCV13 (13‑valent PCV) in 2010. We aimed to synthesize evidence on the population effects of PCVs on invasive pneumococcal disease (IPD) in Canada.
METHODS: A targeted literature review was conducted to identify studies published between January 2016 and February 2025 that reported IPD incidence rates before and after PCV7 or PCV13 introduction in Canada. Trends in incidence rates (IRs) and percentage changes before and after each PCV introduction were summarized.
RESULTS: Eleven surveillance studies (2 national, 9 regional) were included: 6 reported IRs for PCV7 serotypes (VT7), 7 reported IRs for PCV13-non-PCV7 serotypes (VT13-non-VT7), and 8 reported IRs for non-PCV13 serotypes (NVT). VT7 IRs decreased by 36%−100% after PCV7 introduction, with the greatest reductions observed among young children (<5 years). After PCV13 introduction, VT7 IRs continued to decline or remained low. At the national level, VT13-non-VT7 IRs increased by 533%−660% after PCV7 introduction, but decreased by 44%−90% following PCV13 introduction, with the largest declines observed among young children (83%−90%). Trends in VT13-non-VT7 IRs varied considerably by region and age group; for example, increases in IRs were observed among adolescents and adults in British Columbia. NVT IRs exhibited an upward trend following PCV introduction, increasing by 13%−143% in the PCV13 period compared to pre-PCV13 across regions and age groups. Overall IPD IRs generally declined among young children; however, trends varied substantially across older age groups and regions.
CONCLUSIONS: The incidence of vaccine-type IPD declined after PCV7 and PCV13 introductions across age groups at the national level in Canada, consistent with both direct and herd protection effects. The incidence of non-vaccine-type IPD increased following PCV introduction, suggesting widespread serotype replacement. Overall IPD IRs did not show consistent trends across age groups and regions.
METHODS: A targeted literature review was conducted to identify studies published between January 2016 and February 2025 that reported IPD incidence rates before and after PCV7 or PCV13 introduction in Canada. Trends in incidence rates (IRs) and percentage changes before and after each PCV introduction were summarized.
RESULTS: Eleven surveillance studies (2 national, 9 regional) were included: 6 reported IRs for PCV7 serotypes (VT7), 7 reported IRs for PCV13-non-PCV7 serotypes (VT13-non-VT7), and 8 reported IRs for non-PCV13 serotypes (NVT). VT7 IRs decreased by 36%−100% after PCV7 introduction, with the greatest reductions observed among young children (<5 years). After PCV13 introduction, VT7 IRs continued to decline or remained low. At the national level, VT13-non-VT7 IRs increased by 533%−660% after PCV7 introduction, but decreased by 44%−90% following PCV13 introduction, with the largest declines observed among young children (83%−90%). Trends in VT13-non-VT7 IRs varied considerably by region and age group; for example, increases in IRs were observed among adolescents and adults in British Columbia. NVT IRs exhibited an upward trend following PCV introduction, increasing by 13%−143% in the PCV13 period compared to pre-PCV13 across regions and age groups. Overall IPD IRs generally declined among young children; however, trends varied substantially across older age groups and regions.
CONCLUSIONS: The incidence of vaccine-type IPD declined after PCV7 and PCV13 introductions across age groups at the national level in Canada, consistent with both direct and herd protection effects. The incidence of non-vaccine-type IPD increased following PCV introduction, suggesting widespread serotype replacement. Overall IPD IRs did not show consistent trends across age groups and regions.
Conference/Value in Health Info
2026-05, ISPOR 2026, Philadelphia, PA, USA
Value in Health, Volume 29, Issue S6
Code
EPH41
Topic
Epidemiology & Public Health
Topic Subcategory
Public Health
Disease
STA: Vaccines