Public communication surrounding controversial risk and policy issues is often characterized by competitive messaging, whereby different messengers compete to frame these risk issues in ways that they believe will shift public and policymaker opinions in favor of their interests. Inoculation is a long-standing persuasion theory that describes framing and responses to risk issues. Prior research suggests that inoculation messages can confer resistance to persuasion by another competing message. This dissertation expanded inoculation theory by testing people’s tendency to approach or avoid competing messages after being inoculated. If an inoculation message makes people more likely to proactively seek out competing information, they might be susceptible to persuasion from competing information compared to other messaging strategies that do not encourage people to explore competing information. Studies 1 and 2 served as pilot tests, examining the effects of inoculation messages on people’s selective exposure to counter-attitudinal messages and subsequent persuasive outcomes in the context of gun laws. It further explored how these effects differed among people whose initial attitudinal position was either consistent or inconsistent with the inoculation message advocated position. Study 3 replicated the initial experiment to test the robustness of its findings. Studies 4 and 5 pretested constructs and stimuli that were used in the final experiment. Study 6, the final experiment, focused on testing hypotheses regarding the impact of inoculation on selective exposure and persuasion outcomes, expanding the context to include nuclear energy and enhancing ecological validity by incorporating diverse article types on mock webpages. In Study 1, counter-attitudinal inoculations induced strong confirmation bias and significantly shifted policy support toward the inoculation advocated position, while pro-attitudinal inoculations did not. This was not replicated in Study 3, where both pro-attitudinal and counter-attitudinal inoculations induced confirmation bias without shifting attitudes. Study 6 found varied effects depending on the issue (gun laws or nuclear energy), with a marginal protective effect of pro-attitudinal messages on policy support for nuclear energy, and introduced more complex selective exposure patterns. This research can offer risk communicators theory-informed guidance on how to better employ an inoculation strategy to communicate with audiences in today’s high-choice media environment. Findings also shed light on the effects of risk messages among members of the public who hold a wide range of preexisting issue positions for controversial risk issues.