The world’s attention is presently focused on the mRNA vaccines, which may turn out to be the most revolutionary vaccines ever produced. However, very few doctors, and certainly not the public, have any awareness at all of the nonspecific effects of vaccines (NSEs). The specific effect of a vaccine is immunity to a target infection; the nonspecific effect refers to the off-target effects of all vaccines. These can be positive or negative. The beneficial effects are improved immunity to a variety of infections and all-round health, and the negative effects are the inverse—a predisposition to off-target diseases and immune dysregulation, whilst still conferring immunity to the targeted pathogen. These discoveries have surprised the scientific community and left researchers scratching their heads as to how and why such important effects could have been overlooked by epidemiologists for over a century.