- Access to other Advances
Epidemic disease has laid more empires waste than all the human armies in history. Whenever people congregated in cities, infectious diseases followed them. The discovery that people could be protected from infection by inoculating them was a huge step forward in the quality and length of life for all people.
Plagues were such a fact of historical life that they were for millennia regarded as inevitable. As humans became thick enough on the ground that disease could spread from person to person, not only human but also animal-source diseases decimated human populations regularly. Plague struck Athens in the Peloponnesian War, killing 1/3 to 2/3 of the population. Plagues struck Imperial Rome almost regularly from the 3rd century AD, reducing the entire Empire’s population. The Black Death (Bubonic Plague) wiped out half of all Europeans in the 14th century. The list is almost endless. This deadly cycle was broken at the end of the 18th century, when Edward Jenner in England began researching into why milkmaids rarely caught the deadly smallpox. After twenty years’ research he developed a vaccine or immunization against smallpox, based on the related cowpox virus that had effectively immunized the maids in closest contact with the infected cows. Immunization was applied to fight a host of infectious diseases, such as measles, small pox, yellow fever, and influenza. All of these had throughout history killed millions, but by 1979 smallpox was declared officially eradicated because of virtually universal smallpox inoculations in the previous 50 years.