These human tragedies all have one thing in common. The villain in each case previously mentioned is another life form. A life form, when examined under a powerful microscope, is more alien than anything ever dreamed of by science fiction writers. There is a branch of science, which recruits from various fields of biology and medicine. The warriors in this war, are called epidemiologists.
Epidemiology is the study of the distribution and causes of disease in populations.
Like all warriors, weapons are needed to fight the enemy. Weapons like vaccinations, antibiotics, anti-viral injections, and numerous methods to identify the enemy are used. In any war, civilians are involved. It is your responsibility to make sure that all immunizations are up-dated when needed. See your doctor and ask about your vaccinations.