Vaccination
Due to several breakthroughs in medical science, humans can now lead longer lives. Back then, people died of diseases like smallpox and mumps. Fortunately, an English surgeon called Edward Jenner discovered an effective way to revolutionize medicine for good.

He is the mastermind behind vaccines. Although the man couldn’t have known it back then, his invention eradicated multiple viruses, controlled dozens of diseases, and saved thousands of lives. Talk about changing the world!