Learning Objectives for this Presentation:
By the end of the presentation participants will be able to describe trends in administration of MCV4 and Tdap in Michigan.

Background:
The FDA approved meningococcal conjugate vaccine (MCV4) in January 2005 and a pertussis-containing vaccine for adolescents (Tdap) in June 2005. Most vaccine providers in Michigan use the MCIR to enter or obtain information about patients' immunizations, producing an extensive and timely data source that can be used to analyze the adoption of new vaccines.

Objectives:
Examine the acceptance of MCV4 and Tdap using MCIR data, and the extent to which they replace meningococcal polysaccharide vaccine (MPSV) or tetanus-diphtheria toxoid (Td), respectively.

Methods:
Numbers of MCV4 and meningococcal polysaccharide vaccine (MPSV) administered each month were charted. Age at administration and vaccine funding source (public/private) were also examined. A similar process was used to examine Tdap and Td.

Results:
In 2004 and 2005, most meningitis vaccination occurred in the months of June, July, and August, August being highest. Few meningitis vaccinations occurred in winter or spring. The number of meningitis vaccines given to 17 or 18 year olds from May through October increased by 74% from 2004 to 2005. All such vaccines given in 2004 were MPSV; however, of the 15,000 such vaccines recorded for 2005, 20% were MPSV and 80% were MCV4. In both years, about 54% were given by public providers.
Little data for Tdap is available at this writing, but results are expected in early 2006.

Conclusions:
In 2005, many more adolescents received meningitis vaccine, and MCV4 largely supplanted MPSV. Such information is timely; the MCV4 analysis was first performed in August 2005 and yielded similar results. This analysis will be repeated for other vaccines (MMRV, rotavirus, HPV, etc.).