In the United States, annual influenza epidemics kill approximately 36,000 people, seriously hospitalize 200,000, and cause substantial social and economic disruption. Fortunately, vaccination is considered an effective prevention method. However, despite recommendations by the Centers for Disease Control and Prevention (CDC), annually only 40% of healthcare workers are immunized against influenza. Such low rates present challenges not only to patient health, but also the delivery of medical services.

There is no magic formula for increasing influenza vaccine uptake among healthcare workers. Only a multi-faceted approach involving communication, cost controls and supply stability will achieve the desired result. This thesis focuses specifically on the role of vaccine communication in facilitating changes in immunization behavior. It argues that public health officials need to understand how healthcare workers make personal vaccine decisions and what informs those choices. Moreover, it provides commentary on the logistical, social and ethical issues this approach raises.

Overall, this thesis?s guiding question is as follows: What are the determinants of vaccine behavior among healthcare workers in various settings? Specifically, it focuses on how vaccine information is sought and cognitively interpreted, and how these actions influence immunization decisions. A model of risk information seeking and processing (RISP) is used as a guiding framework. This model explores motivations for information seeking and processing (i.e. systematic and heuristic), and their relationships to various components of behavior (e.g., attitudes, beliefs, and intentions). It posits that systematic processing, when paired with information seeking, is associated with a higher number of beliefs one considers, as well as (ultimately) attitudinal stability and enduring behavior change. Given that influenza vaccination is a behavior repeated throughout one?s life, the focus on enduring change is particularly appealing.

This thesis is a ?first step? in exploring the relationship among vaccine information seeking and processing, and the aforementioned components of behavior. One hundred twenty-one in-person, telephone, and online interviews were conducted with physicians, nurses, paramedics and other groups within an urban community in central New York. Research goals included: (1) providing preliminary data on these cognitive behaviors, (2) developing measurements for several RISP model variables in need of further exploration, and (3) creating a foundation for future research with healthcare workers or other population groups. Study variables, derived from the RISP model, included: (a) information processing/seeking indicators, (b) preferred information sources, (c) perceived ability to find information, (d) salient beliefs about vaccination and (e) attitudes towards vaccine sources.

Overall, the data suggest that healthcare workers consider a variety of beliefs in deciding whether to be immunized. Beliefs associated with vaccination included the protection of personal health and patient well-being. Beliefs against immunization included lack of perceived risk for influenza, time constraints, and concern about side effects. Regarding information seeking, interviewees tended to favor health-related sources for vaccine information, including the CDC and their local health department.

Additionally, several measurements for heuristic and systematic processing were developed. Measures for systematic processing included relating the information to one?s responsibilities as a healthcare worker and considering one?s existing vaccine-related attitudes. Those for heuristic processing included: focusing on the length, clarity, and visual aspects of vaccine information. Finally, several theoretical and practical implications were discussed. Theoretically, two new variables were identified which may help delineate various gradients of information seeking beyond mere presence or absence. Practically, the data suggest that perceptions of information quality likely interact with vaccine-specific judgments in informing immunization decisions. Vaccine information that addresses key vaccine-related concerns and questions, as well as provides clear rationale for recommendations, will likely be most effective in achieving effectiveness and legitimacy.