Emil von Behring was a German physician and Nobel laureate who developed the first antitoxin for diphtheria, revolutionizing modern medicine.
Jonas Salk was an American medical researcher and virologist who developed the first safe and effective polio vaccine, transforming global public health.
Max Theiler was a South African virologist who developed the first successful yellow fever vaccine, earning him the Nobel Prize in Physiology or Medicine in 1951.