English: Diagram showing an example of the base rate fallacy, using Covid hospitalization rates. The 50% versus 10% hospitalization rates are extremely exaggerated and should be read as just an illustration. Covid never had a 50% hospitalization rate. A better comparison would use more realistic hospitalization rates in different age groups. After testing became less common it is highly uncertain how many people are infected with covid. The effectiveness of the commonly used vaccines against the novel variants of covid is likewise uncertain. In the example, there are more vaccinated people than unvaccinated people hospitalized (leftmost circle), but that's only because in the general population there are more vaccinated people than unvaccinated (rightmost diagram, with green circle representing the unvaccinated population, pink circle representing the vaccinated population, and the black circle representing hospitalized people. This diagram is just a visual made to illustrate the concept, not a specific data set.