Low Rates of Influenza Immunization in Young Children Under Ontario’s Universal Influenza Immunization Program
Campitelli MA et al. – Influenza vaccine coverage among children aged 6 to 23 months in Ontario is low, despite a universal vaccination program and high primary care visit rates. Interventions to improve coverage should target both physicians and families.Methods
- By using hospital records, they identified all infants born alive in Ontario hospitals from April 2002 through March 2008.
- Immunization status was ascertained by linkage to physician billing data.
- Children were categorized as fully, partially, or not immunized depending on the number and timing of vaccines administered.
- Generalized linear mixed models determined the association between immunization status and infant, physician, and maternal characteristics.
- Influenza immunization was low for the first influenza season of the study period (1% fully immunized during the 2002–2003 season), increased for the following 3 seasons (7% to 9%), but then declined (4% to 6% fully immunized during the 2006–2007 to 2008–2009 seasons).
- Children with chronic conditions or low birth weight were more likely to be immunized.
- Maternal influenza immunization (adjusted odds ratio 4.31; 95% confidence interval 4.21–4.40), having a pediatrician as the primary care practitioner (adjusted odds ratio 1.85; 95% confidence interval 1.68–2.04), high visit rates, and better continuity of care were all significantly associated with full immunization, whereas measures of social disadvantage were associated with nonimmunization.
- Low birth weight infants discharged from neonatal care in the winter were more likely to be immunized.