Yellow Fever Vaccine — Max Theiler (1937)

Max Theiler’s yellow fever vaccine, developed in 1937 at the Rockefeller Foundation, provides lifelong immunity from a single dose, earning Theiler the 1951 Nobel Prize for this breakthrough. It has prevented an estimated 50,000 deaths annually during outbreaks, and its efficacy rate of 95% at 30 days post-injection is 10% higher than that of the BCG vaccine (#7) against severe childhood TB forms. The vaccine’s stability is notable, with a shelf life of three years at standard refrigeration, ensuring reliability in tropical regions. This achievement remains critical for controlling outbreaks across Africa and South America, demonstrating a lasting impact over nearly 90 years.