The "father of vaccines" – cool story. Jenner figured out that getting people sick with cowpox (a mild disease) made them much less likely to be killed by smallpox (a serious disease). There was already a practice called variolation which was just straight-up infecting people with smallpox. And here is the origin of the name vaccine. Cowpox is translated into Latin as variolae vaccinae ("cow's smallpox"). So giving people cowpox is called "vaccination".

Now vaccination is the general practice of infecting people with a mild variant of a deadly disease. Often a mild variant doesn't exist, so we craft one in the lab.

Came up with an idea for disinfecting wounds, and by now he could rest his arguments on Pasteur's work, unlike Semmelweiss who lived too early.

After a bunch of people advised the USGov to build an atomic bomb, Oppenheimer was tasked with overseeing the project at Los Alamos. Seeing the first ever nuke go off, he regretted his participation, saying "I am become Death, destroyer of worlds".