The messenger for the campaign will also include some of the many sponsors that have already been assembled for the development phase of the social marketing campaign. These groups include the WSDOH, Community Pediatric Foundation of Washington, Seattle Children's Hospital, Group Health Foundation, and Within Reach, a private nonprofit organization whose mission is to serve as the foremost catalyst for improvements in maternal, child, and family health. Nonprofit organizations are instrumental to the messenger strategy, as they often are perceived as more trustworthy than people or organizations that are paid to endorse a product. A vaccine manufacturer encouraging childhood immunization, for instance, naturally provokes skepticism about motives. An example of a current social marketing campaign on immunizations using an effective partnership is the “i choose” campaign in California, which is sponsored by the California Department of Health, the California Immunization Coalition, University of California–Berkeley CAL Hep B Free, and Alameda County Immunization Coalition.46