Rachel D Savage1, Christopher A Bell2, Christiaan H Righolt3, Krista Wilkinson3, Kevin L Schwartz4, Cynthia Chen5, Shelly Bolotin6, Shelley L Deeks7, Steven J Drews8, Frances B Jamieson9, Caitlin Johnson5, Jeffrey C Kwong10, Salaheddin M Mahmud3, Margaret L Russell2, Kimberley A Simmonds11, Lawrence W Svenson12, Natasha S Crowcroft13. 1. Public Health Ontario, Toronto, ON, Canada; ICES, Toronto, ON, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada. Electronic address: rachel.savage@wchospital.ca. 2. Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada. 3. Vaccine and Drug Evaluation Centre, Department of Community Health Sciences, University of Manitoba, Winnipeg, MB, Canada. 4. Public Health Ontario, Toronto, ON, Canada; ICES, Toronto, ON, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada. 5. Public Health Ontario, Toronto, ON, Canada. 6. Public Health Ontario, Toronto, ON, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada. 7. Public Health Ontario, Toronto, ON, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada. 8. ProvLab Alberta, Edmonton, AB, Canada; Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, Canada. 9. Public Health Ontario, Toronto, ON, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada. 10. Public Health Ontario, Toronto, ON, Canada; ICES, Toronto, ON, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada; Department of Family & Community Medicine, University of Toronto, Toronto, ON, Canada. 11. Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Alberta Health, Edmonton, AB, Canada. 12. Department of Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Alberta Health, Edmonton, AB, Canada; School of Public Health, University of Alberta, Edmonton, AB, Canada; Division of Preventive Medicine, University of Alberta, Edmonton, AB, Canada. 13. Public Health Ontario, Toronto, ON, Canada; ICES, Toronto, ON, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.
Abstract
BACKGROUND: Pertussis remains poorly controlled relative to other diseases targeted by childhood vaccination programs. We combined estimates from four population-based studies of pertussis vaccine effectiveness (VE) in three Canadian provinces using a meta-analytic approach to improve precision and explore regional variation in VE and durability of protection. METHODS: Studies were conducted in Alberta, Manitoba, and Ontario over periods ranging from 1996 to 2015. Adjusted log odds ratios (OR; VE = 100*[1-OR]) of the effect of vaccination on pertussis risk were estimated by time since last vaccination in each study and pooled using DerSimonian and Laird random-effects models. We used the I2 statistic to estimate between-study heterogeneity and assessed methodological and clinical heterogeneity through subgroup analyses of study design and age. RESULTS: Data on 3,270 pertussis cases and 23,863 controls were available. Pertussis VE declined from 86% (95% CI 79%-90%, I2 = 81.5%) at < 1 year since last vaccination to 51% (11%-74%, I2 = 80.9%) by ≥ 8 years. Effect estimates were the most heterogeneous in the least and most elapsed time periods since last vaccine dose. This was attributable mostly to variation between provinces in the distribution of age groups and number of vaccine doses received within time periods, as well as study design and small numbers in the most elapsed time period. INTERPRETATION: Consistent trends of decreasing pertussis VE with increasing time since last vaccination across three Canadian provinces indicate the need for immunization schedules and vaccine development to optimize protection for all individuals, especially for adolescents and young adults at greatest risk of infection. Crown
BACKGROUND: Pertussis remains poorly controlled relative to other diseases targeted by childhood vaccination programs. We combined estimates from four population-based studies of pertussis vaccine effectiveness (VE) in three Canadian provinces using a meta-analytic approach to improve precision and explore regional variation in VE and durability of protection. METHODS: Studies were conducted in Alberta, Manitoba, and Ontario over periods ranging from 1996 to 2015. Adjusted log odds ratios (OR; VE = 100*[1-OR]) of the effect of vaccination on pertussis risk were estimated by time since last vaccination in each study and pooled using DerSimonian and Laird random-effects models. We used the I2 statistic to estimate between-study heterogeneity and assessed methodological and clinical heterogeneity through subgroup analyses of study design and age. RESULTS: Data on 3,270 pertussis cases and 23,863 controls were available. Pertussis VE declined from 86% (95% CI 79%-90%, I2 = 81.5%) at < 1 year since last vaccination to 51% (11%-74%, I2 = 80.9%) by ≥ 8 years. Effect estimates were the most heterogeneous in the least and most elapsed time periods since last vaccine dose. This was attributable mostly to variation between provinces in the distribution of age groups and number of vaccine doses received within time periods, as well as study design and small numbers in the most elapsed time period. INTERPRETATION: Consistent trends of decreasing pertussis VE with increasing time since last vaccination across three Canadian provinces indicate the need for immunization schedules and vaccine development to optimize protection for all individuals, especially for adolescents and young adults at greatest risk of infection. Crown
Authors: Janna R Shapiro; Huifen Li; Rosemary Morgan; Yiyin Chen; Helen Kuo; Xiaoxuan Ning; Patrick Shea; Cunjin Wu; Katherine Merport; Rayna Saldanha; Suifeng Liu; Engle Abrams; Yan Chen; Denise C Kelly; Eileen Sheridan-Malone; Lan Wang; Scott L Zeger; Sabra L Klein; Sean X Leng Journal: NPJ Vaccines Date: 2021-12-09 Impact factor: 7.344