Answer:
The prevention paradox describes a principle of prevention that the individual health gain through preventive interventions is large for people with a high health risk, but that this has only a small effect on the overall population and - conversely - the individual gain for people with a low risk is small despite a considerable overall effect through preventive measures for large parts of the general population.
Thus, when general health measures are applied to the common population, these will only have a noticeable positive effect only in those patients who represent a high risk for the disease to be attacked, but will not have a noticeable effect on a large scale.