1793 Philadelphia yellow fever epidemic immune to the fever. Many of the slaves in Charleston in 1742 could have gained immunity before having been transported from Africa, by having been exposed to yellow fever in a mild case. People who survived one attack gained immunity. A total of 240 blacks died, in proportion to their population at the same rate as whites. Given the limited resources and knowledge of the times, the city's response was credible. The medical community did not know the natural history of yellow fever, a viral infection spread by the "Aedes aegypti" mosquito. Efforts to clean the city did not defeat
Yellow fever The eradication of yellow fever strengthened the relationship between the US and Mexico, which had not been very good in the past. The eradication of yellow fever was also a major step toward better global health. In 1927, scientists isolated the yellow fever virus in West Africa. Following this, two vaccines were developed in the 1930s. The vaccine 17D was developed by the South African microbiologist Max Theiler at the Rockefeller Institute in New York City. This vaccine was widely used by the U.S. Army during World War II. Following the work of Ernest Goodpasture, Theiler used chicken eggs to