Shauna O'Donnell1, Eve Dubé2, Bruce Tapiero3, Arnaud Gagneur4, Margaret K Doll5, Caroline Quach6. 1. Department of Epidemiology, Biostatistics & Occupational Health, McGill University, 1020 Pine Ave., West Montreal, QC H3A 1A2, Canada; Research Institute of the McGill University Health Centre, 1001 Decarie Boul., Montreal, QC H4A 3J1, Canada; Infection Prevention & Control Unit, Department of Medical Microbiology, CHU Sainte-Justine, University of Montreal, 3175 Cote Sainte-Catherine, Montreal, QC H3T 1C5, Canada. 2. Direction des risques biologiques et de la santé au travail, Institut de santé publique du Québec, 945 Avenue Wolfe, Québec, QC G1V 5B3, Canada. 3. Division of Paediatric Infectious Diseases, CHU Sainte-Justine, University of Montreal, 3175 Cote Sainte-Catherine, Montreal, QC H3T 1C5, Canada. 4. Department of Paediatrics, University of Sherbrooke, 3001, 12e Avenue Nord, Sherbrooke, QC J1H 5N4, Canada. 5. Department of Epidemiology, Biostatistics & Occupational Health, McGill University, 1020 Pine Ave., West Montreal, QC H3A 1A2, Canada; Research Institute of the McGill University Health Centre, 1001 Decarie Boul., Montreal, QC H4A 3J1, Canada. 6. Department of Epidemiology, Biostatistics & Occupational Health, McGill University, 1020 Pine Ave., West Montreal, QC H3A 1A2, Canada; Infection Prevention & Control Unit, Department of Medical Microbiology, CHU Sainte-Justine, University of Montreal, 3175 Cote Sainte-Catherine, Montreal, QC H3T 1C5, Canada; Direction des risques biologiques et de la santé au travail, Institut de santé publique du Québec, 945 Avenue Wolfe, Québec, QC G1V 5B3, Canada; Division of Paediatric Infectious Diseases, CHU Sainte-Justine, University of Montreal, 3175 Cote Sainte-Catherine, Montreal, QC H3T 1C5, Canada; Department of Microbiology, Infectious Diseases and Immunology, University of Montreal, C.P. 6128, succ. Centre-ville, Montréal, Québec H3C 3J7, Canada. Electronic address: c.quach@umontreal.ca.
Abstract
BACKGROUND: Under-immunization refers to a state of sub-optimal protection against vaccine preventable diseases. Vaccine coverage for age may not capture intentional or non-intentional spacing of vaccines in the recommended provincial immunization guidelines. We aimed to identify factors associated with coverage and under-immunization and to determine the number of days during which children were under-immunized during their first 24months of life. METHODS: Secondary analysis of children ≤3years recruited through active surveillance for gastroenteritis from three Quebec pediatric emergency departments from 2012 to 2014. Vaccination status for children at least 24months of age was determined using provincial immunization guidelines. Cumulative days under-immunized were calculated for DTaP-VPI-Hib, PCV, MMR, and Men-C-C. Factors associated with up-to-date (UTD) status at 24months of life and for under-immunization ≥6months were analyzed using logistic regression. RESULTS: Of 246 eligible children, 180 (73%) were UTD by 24months of life. The mean cumulative days under-immunized for MMR was 107days, for PCV 209days, for Men-C-C 145days, and for DTaP-VPI-Hib 227days. Overall, 149 children (60%) experienced delay for at least 1 vaccine. Factors associated with both an UTD status at 24months and concurrently associated with being under-immunization ≥6months, included timely initiation of immunization (OR=5.85; 95% CI: 2.80-12.22) and (OR=0.13; 95% CI: 0.07-0.24), failure to co-administer 18-month vaccines (OR=0.15; 95% CI: 0.10-0.21) and (OR=3.29; 95% CI: 2.47-4.39), and having a household with ≥3 children under 18years ((OR=0.50; 0.28-0.86) and (OR=2.99; 1.45-6.22), respectively. CONCLUSION: Paired with an unexpected low level of coverage at 24months of life, the majority of our cohort also experienced a state of under-immunization for a least one vaccine. Estimates of coverage do not capture intentional or non-intentional gaps in protection from vaccine preventable illnesses. Timely preventive care should be prioritized.
BACKGROUND: Under-immunization refers to a state of sub-optimal protection against vaccine preventable diseases. Vaccine coverage for age may not capture intentional or non-intentional spacing of vaccines in the recommended provincial immunization guidelines. We aimed to identify factors associated with coverage and under-immunization and to determine the number of days during which children were under-immunized during their first 24months of life. METHODS: Secondary analysis of children ≤3years recruited through active surveillance for gastroenteritis from three Quebec pediatric emergency departments from 2012 to 2014. Vaccination status for children at least 24months of age was determined using provincial immunization guidelines. Cumulative days under-immunized were calculated for DTaP-VPI-Hib, PCV, MMR, and Men-C-C. Factors associated with up-to-date (UTD) status at 24months of life and for under-immunization ≥6months were analyzed using logistic regression. RESULTS: Of 246 eligible children, 180 (73%) were UTD by 24months of life. The mean cumulative days under-immunized for MMR was 107days, for PCV 209days, for Men-C-C 145days, and for DTaP-VPI-Hib 227days. Overall, 149 children (60%) experienced delay for at least 1 vaccine. Factors associated with both an UTD status at 24months and concurrently associated with being under-immunization ≥6months, included timely initiation of immunization (OR=5.85; 95% CI: 2.80-12.22) and (OR=0.13; 95% CI: 0.07-0.24), failure to co-administer 18-month vaccines (OR=0.15; 95% CI: 0.10-0.21) and (OR=3.29; 95% CI: 2.47-4.39), and having a household with ≥3 children under 18years ((OR=0.50; 0.28-0.86) and (OR=2.99; 1.45-6.22), respectively. CONCLUSION: Paired with an unexpected low level of coverage at 24months of life, the majority of our cohort also experienced a state of under-immunization for a least one vaccine. Estimates of coverage do not capture intentional or non-intentional gaps in protection from vaccine preventable illnesses. Timely preventive care should be prioritized.
Authors: Da In Diane Lee; Shelley Vanderhout; Mary Aglipay; Catherine S Birken; Shaun K Morris; Pierre-Philippe Piché-Renaud; Charles D G Keown-Stoneman; Jonathon L Maguire Journal: Can J Public Health Date: 2022-01-20