Date of Completion


Embargo Period



Vaccine, Source Credibility, Fear, Protection Motivation Theory

Major Advisor

Dr. Kirstie Farrar

Associate Advisor

Dr. Mark Hamilton

Associate Advisor

Dr. David Atkin

Field of Study

Communication Sciences

Open Access

Open Access


The present investigation sought to explore the dual influence source credibility and fear have on childhood vaccination intentions among parents. A 2 x 2 experimental design was used to test the influence messages with manipulated levels of credibility (high/low) and fear (high/low) had on measles, mumps, and rubella (MMR) vaccination intentions among current (or future) parents of young children. Perceptions of source credibility and fear were both found to indirectly influence vaccination intentions. Specifically, the relationship between message exposure and behavioral intent was mediated by various social-cognitive constructs including attitudes, subjective norms, perceived behavioral control, susceptibility to disease, severity of disease and feelings of response efficacy. Implications, limitations and future directions are discussed.