Abstract
Vaccine avoidance often results from cognitive misperceptions, such as unfounded fears, leading to decisions that contradict evidence from organizations like the World Health Organization (WHO), which states that the risks of vaccine-preventable diseases far outweigh vaccine side effects. The Monty Hall paradox - a probability puzzle - demonstrates how individuals frequently fail to update their decisions when presented with new information, due to cognitive biases and misjudged probabilities. This analogy frames vaccine hesitancy as a failure to correctly interpret and act on updated risk information. This article uses the Monty Hall problem to explain vaccine resistance and examines whether decision-making processes regarding vaccination differ between men and women. A survey-based study was conducted with 300 participants from England, France, and Germany in September 2023. Data were collected by Cint, an International Organization for Standardization (ISO) 20252 certified organization specializing in online research, which ensures sample quality through verified respondent information and robust sampling algorithms. Findings indicate that, among men, the likelihood of choosing vaccination increased from 73.3% to 91.5% when shifting from the incorrect to the correct solution of the Monty Hall problem. This effect was not observed among women. These results suggest that integrating probabilistic reasoning models into public education and health campaigns may enhance vaccine uptake, particularly among men. This supports public policy efforts to improve risk literacy by incorporating probability concepts into school curricula, promoting media literacy, and developing decision-support tools for health communication.