One of the problems of the digital age is the increased consumption of false information through various media channels, which was particularly noticeable during the COVID-19 pandemic. Specifically, false information can influence individuals to make incorrect health decisions, such as decisions regarding vaccination, which can consequently lead to negative outcomes for the entire society. Example of such negatives outcomes are re-emergence of diseases like measles or the accelerated spread of the COVID-19 virus. Therefore, there is a need to prevent the effects of misinformation. One proposed method of prevention is prebunking, which has its roots in inoculation theory. Additionally, some researches recommend improving scientific literacy among the population so people can more effectively evaluate the information they consume. The aim of this paper was to examine how the type of warning message and scientific reasoning affect the prevention of the effects of misinformation. Participants were randomly divided into a group that did not receive a warning, a group that received a simple warning, and a group that received an elaborate warning. Furthermore, they were presented with a text containing false information, after which they completed a scale measuring their attitudes towards vaccination. Finally, they completed the Scientific Reasoning Scale in the Croatian translation. The results of this study did not confirm a significant main effect of the warning message variable, a significant main effect of the level of scientific reasoning, nor their interaction on participants attitude towards mRNA vaccines. Nevertheless, this study can provide information that can be used for further research on the problem of preventing the effects of misinformations.