Message framing, identity congruence, and polio vaccine acceptance in Pakistan: Testing a social identity-based communication framework.

The transition from traditional biomedical-based vaccination campaigns in Pakistan has faced many difficulties. This paper proposes that the central problem is not the content of vaccine-related messages per se, but whether their targets perceive those messages as aligned with their identities. The objective of this study is to examine the effects of message framing and perceived identity threat on polio intention to vaccinate through the theoretical perspectives of Framing Theory and Social Identity Theory (SIT). A survey sample of 600 adults in Sindh and Balochistan, two regions understudied in empirical research on this topic, was employed. Hierarchical multiple regression and moderation analyses were used to test the hypotheses. Collective identity framing was the most significant positive predictor of intention to vaccinate (β = .41, p < .001). Identity threat, the perception that an anti-polio message contradicts the respondents' religious or cultural identity, was the strongest negative predictor (β = -.45, p < .001). Peer-norm salience significantly mediated the link between framing uptake and collective framing among community-oriented respondents. Critically, religious commitment was non-significant once identity threat was controlled, demonstrating that identity threat, not religiosity, is the proximal driver of refusal. The Identity-Anchored Message Uptake (IAMU) Model is proposed based on these findings.