Abstract
Objective
Premature children are at increased risk of complications from vaccine-preventable diseases and should be vaccinated with the routinely recommended childhood vaccines at the same chronological age as full-term infants with the exception of the hepatitis B vaccine for infants of HBsAg-positive mothers. We sought to compare on-time vaccination levels in premature children for recommended vaccinations to levels in children born at term.
Methods
Using linked health administrative databases, we compared the proportion of term (37+ wks), near term (33-36 wks), very premature (28–32 wks) and extremely premature (≤27 wks) children who received at least one vaccination during the 2-, 4- and 6-month vaccination visits within the recommended time period in the province of Ontario.
Results
When we excluded children who were hospitalized at any time during the vaccination window, we identified that vaccination rates were within 3% of each other in the 4 categories examined. However, when we included infants who may have been hospitalized at any point during the on-time window, we observed substantially lower rates in the extremely premature children at 2 and 4 months and in the very premature children at 2 months.
Conclusion
Our study identifies the need to confirm whether vaccinations are given while premature children are in hospital during the time of their scheduled vaccinations.
Key words: Vaccination, immunization, infant, premature, Ontario, health services research
Résumé
Objectif
Les enfants prématurés courent un risque accru de complications des maladies évitables par la vaccination; ils devraient donc recevoir les vaccins infantiles systématiquement recommandés au même âge chronologique que les nourrissons nés à terme, à l’exception du vaccin contre l’hépatite B pour les nourrissons de mères séropositives pour l’AgHBs. Nous avons voulu comparer, pour les vaccins recommandés, les niveaux de vaccination à temps des enfants prématurés à ceux des enfants nés à terme.
Méthode
À l’aide de bases de données sanitaires administratives liées, nous avons comparé la proportion d’enfants nés à terme (37+ sem.), légèrement prématurés (33-36 sem.), très prématurés (28-32 sem.) et extrêmement prématurés (≤27 sem.) ayant reçu au moins un vaccin durant leurs visites de vaccination à 2, 4 et 6 mois dans les délais recommandés dans la province de l’Ontario.
Résultats
En excluant les enfants hospitalisés à un moment donné durant la fenêtre de vaccination, nous avons constaté que les taux de vaccination se situaient dans une proportion de 3 % les uns des autres dans les quatre catégories examinées. Cependant, en incluant les nourrissons ayant pu être hospitalisés à un moment donné durant la fenêtre de vaccination, nous avons obtenu des taux considérablement plus faibles dans la catégorie des enfants extrêmement prématurés à 2 et à 4 mois, et dans celle des enfants très prématurés à 2 mois.
Conclusion
Notre étude souligne le besoin de confirmer si les vaccins sont administrés aux enfants prématurés lorsqu’ils sont hospitalisés au moment de recevoir les vaccins prévus.
Mots clés: vaccination; immunisation; nourrisson, prématuré; Ontario; recherche sur les services de santé
Footnotes
Funding: This study was supported by Public Health Ontario, and by the Institute for Clinical Evaluative Sciences (ICES), which is funded by an annual grant from the Ontario Ministry of Health and Long-Term Care (MOHLTC). The opinions, results and conclusions reported in this paper are those of the authors and are independent from the funding sources. No endorsement by ICES, Ontario MOHLTC or Public Health Ontario is intended or should be inferred. Dr. Wilson is supported by the Canada Research Chair in Public Health Policy. Dr. Manuel is supported by the CIHR Chair in Applied Public Health. Dr. Kwong is supported by a Career Scientist award from the Ontario MOHLTC.
Conflict of Interest: None to declare.
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