Learning Objectives for this Presentation:
By the end of the presentation participants will be able to describe influenza vaccine rates in pediatric practices with registry/reminder systems during years with and without vaccine shortages.

Background:
Due to shortage of influenza vaccine during the 2004-2005 season, ACIP recommended vaccination be limited to highest-risk priority groups.

Objectives:
To assess whether practices with an immunization registry and reminder systems were able to 1) selectively target children with high risk conditions (HRCs), 2) vaccinate these children earlier in the season compared to healthy children and 3) maintain immunization rates for these children during the 2004-2005 vaccine shortage.

Methods:
We compared receipt of > 1 vaccine and timing of vaccination during the 2003-2004 and 2004-2005 seasons in children 24-72 months old with and without a HRC in 4 Denver pediatric practices with an immunization registry. During both seasons, the practices sent reminder letters to 24-72 month olds with HRCs but not to healthy children.

Results:
In 2003-2004, the immunization rate for children with HRCs was 62% (719/1,166) compared to 41% (4,189/10,117) for healthy children (p< 0.0001); during 2004-2005, these rates were 60% (627/1,053) and 28% (2,857/10,387; p<0.0001). The mean time to vaccination from 9/1/03 was 65 days (SD 0.8) for children with HRCs and 72 days (SD 0.3) for healthy children (p< 0.0001). The mean time from 9/1/04 was 50 days (SD 1.0) for children with HRCs and 63 days (SD 0.8) for healthy children (p<0.0001). The immunization rate for children with HRCs was unchanged in 2003-2004 vs. 2004-2005 (62% vs. 60%, p=0.3), but for healthy children the rate decreased by 13% (41% vs. 28%, p<0.0001).

Conclusions:
Pediatric practices with a registry and reminder system maintained high immunization rates in children with HRCs even during a season with vaccine shortages and were able to immunize these children earlier in the season compared to healthy children.