Influenza vaccination rates in Ontario children: Implications for universal childhood vaccination policy

The aims of this study were to estimate influenza vaccination coverage for children during the 2006–2007 influenza season in Ontario, Canada, where universal vaccination is available, and to compare the rate among children aged 6–23 months with corresponding rates from other Canadian provinces that specifically target this high-risk group. We conducted a telephone survey of caregivers of children aged 6 months–11 years that included 4854 children from 3029 households. Ontario's vaccination rate (complete and partial coverage combined) for children aged 2–11 years was 28.3% (95% CI 26.3–30.5%) for healthy children and 36.8% (95% CI 31.4–42.5%) for those with chronic conditions. Immunization coverage of children aged 6–23 months was 24.0% (95% CI 20.6–27.7%) in Ontario, similar to Manitoba's rate of 24.1% but lower than rates in other provinces: Nova Scotia (35.5%), Quebec (41.8% for 1 year olds and 37.7% for 2 year olds during the 2005–2006 season), Saskatchewan (32.5%) and Alberta (52.2%). Universal vaccination in Ontario has achieved modest coverage in children aged 2–11 years, but has been less successful than targeted programs in vaccinating infants aged 6–23 months.