Influenza vaccination coverage: findings from immunization information systems

Abstract

BackgroundBeginning with the 2004–05 influenza season, the Advisory Committee on Immunization Practices (ACIP) strengthened their existing encouragement that children aged 6–23 months receive influenza vaccination by creating a formal recommendation.MethodsWell-functioning sentinel project immunization information systems (IIS) in Arizona (AIIS) and Michigan (MIIS) were used to calculate vaccination coverage among children aged 6–23 months during the 2004–05 influenza season. We calculated 2 measures of vaccination coverage: a) receipt of 1 or more doses of influenza vaccine September 2004-March 2005 and b) receipt of 2 or more doses (ie, fully vaccinated). We compared the dose administration distribution among children needing 1 and 2 doses and by provider type. Coverage by age and timeliness of vaccine doses entered into the IIS were also analyzed.ResultsInfluenza vaccination coverage levels among children were 30% and 27% in AIIS and MIIS, respectively, for receipt of 1 or more doses; 13% and 11% of children, respectively, were fully vaccinated. Peaks in dose administration among children needing 1 and 2 doses were similar. There were differences in vaccine administration between public and private providers. Coverage was higher among younger children and over 75% of all influenza vaccine doses were entered into the IIS within 30 days after receipt of vaccine.ConclusionThough almost 1/3 of children received 1 or more doses of vaccine in 2 IIS sentinel projects during the first season of the new recommendation, emphasis needs to be placed on increasing the proportion of children fully vaccinated. IIS data can be used for timely monitoring of vaccination coverage assessments.

Use of the vaccination register to evaluate influenza vaccine coverage in seniors in the 2010/11 influenza season, Navarre, Spain

“…Vaccination registries have been shown to be useful in clinical assessment and in estimating coverage [12]. In Navarre, the vaccine register is used primarily so that physicians and nurses can consult the vaccine status of their patients at any time and to programme the dates to administer the doses of the vaccine schedule.…”

Immunization information and population data sources

“…Studies examining the quality of data in IISs have shown that these data are often incomplete and inaccurate [16][17][18]. Other documented issues are timeliness of reporting [19,20] and coverage, or the percentage of children in a population with a record in an IIS [19,21].…”

The use of immunization registry-based data in vaccine effectiveness studies

“…IISs collect and consolidate records of vaccinations from multiple health care providers and across care settings. These surveillance systems have been shown to provide better immunization delivery by assisting in medical decision-making, reminder recall, determining coverage levels, and identifying pockets of need [10][11][12][13][14][15]. IISs can be used in VE studies to measure the degree of vaccine uptake in a variety of settings and populations by identifying confirmed VPD cases and/or confirming immunization history.…”