Abstract
OBJECTIVES: Pneumococcal infections constitute an important public health problem in Nordic regions of Canada. Nordic populations are not included in national and provincial immunization surveys and there is no centralized immunization registry in these regions. The objective of this study was to estimate pneumococcal vaccination coverage and delays in immunization of children in Nunavik, Quebec.
METHODS: Immunization records of children born in 1994-2005 were collected in all villages. Children were classified into three groups: born in the period January 1, 1994 to April 30, 1997 and targeted by the 2002 mass campaign with the 23-valent polysaccharide vaccine (PPSV23); born in the period May 1, 1997 to March 31, 2002 and targeted by the 7-valent conjugate vaccine (PCV7) catch-up campaign; born in the period April 1, 2002 to December 31, 2005 and targeted by the PCV7 routine infant program.
RESULTS: In the first group (n=896), 86.8% (95% CI: 84.4%-89.0%) were vaccinated with PPSV23. In the second group (n=1,252), 84.3% (95% CI: 82.1%-86.2%) received ≥1 PCV7 dose. In the third group, 90.4% (95% CI: 88.5%-92.1%) received 4 PCV7 doses. Delays >4 weeks in vaccine administration were observed for 26.3% of doses. There were substantial variations between villages for all indicators.
CONCLUSIONS: In the challenging setting of a Nordic and remote region, uptake rates of pneumococcal vaccines in Nunavik were found to be similar to those measured in population surveys in Quebec.
Key Words: Streptococcus pneumoniae, pneumococcal vaccines, immunization, infectious diseases, Aboriginal health
Résumé
OBJECTIFS : Les infections pneumococciques représentent un important problème de santé publique dans les régions nordiques du Canada. Les populations nordiques ne sont pas incluses dans les enquêtes de couverture vaccinale nationales et provinciales. Un registre centralisé de couverture vaccinale n’existe pas dans ces régions. L’objectif de cette étude était d’obtenir des estimés de couverture vaccinale pneumococcique et des retards vaccinaux chez les enfants du Nunavik, Québec.
MÉTHODOLOGIE : Les données de couverture vaccinale des enfants nés entre 1994 et 2005 ont été collectées dans tous les villages. Les enfants ont été regroupés en trois cohortes: ceux nés dans la période du 1er janvier 1994 au 30 avril 1997 et visés par la campagne d’immunisation de masse au VPP-23v de 2002; ceux nés dans la période du 1er mai 1997 au 31 mars 2002 et éligibles au programme de rattrapage au VPC-7; ceux nés dans la période du 1er avril 2002 au 31 décembre 2005 et éligibles au programme d’immunisation de routine au VPC-7.
RÉSULTATS : Dans la 1ère cohorte (n=896), 86,8 % (95% IC: 84,4 %-89,0 %) ont été vaccines au VPP-23v. Dans la 2e cohorte (n=1252), 84,3 % (95% IC: 82,1 %-86,2 %) ont reçu une dose de VPC-7 ou plus. Dans la 3e cohorte, 90,4% (95% CI: 88,5 %-92,1 %) ont reçu 4 doses de VPC-7. Un retard de plus de 4 semaines dans l’administration du VPC-7 a été observé pour 26,3 % de l’ensemble des doses administrées. Des variations substantielles ont été observées entre les villages pour tous les indicateurs.
CONCLUSION : Dans la configuration complexe d’une région nordique et isolée, les taux de couverture au VPC-7 au Nunavik sont similaires à ceux retrouvés dans les enquêtes populationnelles du Québec.
Mots Clés: streptococcus pneumoniae, vaccins pneumococciques, immunisation, maladies infectieuses, santé, des populations autochtones
Footnotes
Funding: This study was funded by the International Polar Year Program of the Canadian Government, administered by the Canadian Institutes of Health Research (Contract # 2008 04 POL–193340–CFBA–56916). The sponsor had no role in the design and conduct of the study, collection, management, analysis and interpretation of the data, or preparation, review and approval of the manuscript.
Conflict of Interest: During the last year, Philippe De Wals received research grants and reimbursements of travel expenses from vaccine manufacturers, including Glaxo-Smith-Kline, Novartis, Sanofi Pasteur, Merck and Pfizer, as well as from governmental agencies, including the Quebec Ministry of Health and Social Services and the Public Health Agency of Canada. None of the other authors have conflicts to declare.
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