Dr. Snow believed sewage dumped into the river or into cesspools near town wells could contaminate the water supply, leading to a rapid spread of disease. In August of 1854 Soho, a suburb of London, was hit hard by a terrible outbreak of cholera.
The pandemic was the work of a 'super-virus' The 1918 flu spread rapidly, killing 25 million people in just the first six months. ... It's now thought that many of the deaths were due to the development of bacterial pneumonias in lungs weakened by influenza.
The WHO recommends strategies on how to prevent malaria transmission by controlling the mosquito population and on how to diagnose and treat malaria infections. There are two main prevention methods: Protective bed nets treated with long-lasting insecticides prevent bites from malaria-infected mosquitoes and kill them.
Edward Jenner. In 1775 Jenner began to study the relationship between cowpox (a comparatively harmless disease) and the more dangerous and disfiguring smallpox. ... He hypothesized that exposure to cowpox rendered the body immune from smallpox. After nearly twenty years of experiments, he developed the first vaccine.
I don't know how effective the shot was sorry
sources: knarf.english.upenn.edu/People/jenner.html
https://www.greenfacts.org/en/malaria/l-2/2-prevention-treatment-strategies.htm
https://www.smithsonianmag.com/.../ten-myths-about-1918-flu-pandemic-180967810/
www.ph.ucla.edu/epi/snow/snowcricketarticle.html