Immunization registry-based recall for a new vaccine.

BACKGROUND: Immunization recall for specific vaccines may be necessary to catch up" children with newly available vaccines or recall children after vaccine shortages. The extent to which immunization registry-based recall can increase immunization rates for a new vaccine has not been prospectively studied. OBJECTIVE: To assess the efficacy of letter/telephone recall for immunization with pneumococcal conjugate vaccine (PCV7) in an economically disadvantaged urban population. DESIGN/METHODS: Randomized controlled trial at an inner-city teaching hospital. Using an immunization registry we randomly assigned children aged 6 weeks to 22 months unimmunized for PCV7 to an intervention group (n = 610) or a control group (n = 624). The intervention consisted of letter and telephone recall for PCV7 vaccination. Two months after intervention receipt of 1 or more doses of PCV7 was assessed. Intention-to-treat analysis was used. RESULTS: We were unable to successfully contact 42.3% of the intervention subjects by mail a