The current study considers how an entertainment narrative about childhood vaccination influences related attitudes. We consider the role of counterarguing in narrative persuasion by integrating extant research and theory to test cognitive mechanisms of narrative persuasion, namely self-referencing and positive issue-related thoughts. Results of this experiment show that exposure to a television narrative depicting the importance of the measles, mumps, and rubella (MMR) vaccine led to more favorable attitudes toward childhood vaccination as compared to a control group. As expected by narrative persuasion theorizing, transportation into the narrative predicted vaccine attitudes. In contrast to typical theorizing and some empirical results, counterarguing did not mediate that relationship, however, self-referencing and positive issue-related thinking did. Theoretical contributions and suggestions for future research expanding our understanding of issue-related thoughts are discussed.