Comparison of Conscientious Exemptions to Immunization and Pertussis Disease in Texas

Background:
Previous studies have indicated that children with exemptions are at increased risk of contracting and transmitting vaccine-preventable diseases. Texas began allowing exemptions from immunizations based on reasons of conscience, including religious beliefs, on September 1, 2003. Clustering of nonmedical exemptions may affect community risk of vaccine-preventable diseases.

Objectives:
To determine whether there is an association between areas of high numbers of reported cases of pertussis disease and areas of high concentration of requests for conscientious exemptions.

Methods:
In order to determine whether an association exists between pertussis disease and immunization exemptions, the 2005-2007 vaccine-preventable surveillance data for pertussis disease (post-exemption years) will be plotted along with 2005-2007 zip code data on the requests for the conscientious exemption using Geographic Information Systems (GIS) software. In addition, a comparison between pre-exemption years (2000-2002) of disease data will be compared with post-exemption years (2005-2007) to determine whether there is a statistical difference.

Results:
Results from our analysis will be presented at the National Immunization Conference.

Conclusions:
Information from the results of this study will help determine whether there is an association between the high incidence of pertussis disease in Texas and the number of conscientious exemption requests.