1793 Philadelphia yellow fever epidemic 1793 Philadelphia yellow fever epidemic During the Yellow Fever Epidemic of 1793 in Philadelphia, 5,000 or more people were listed in the official register of deaths between August 1 and November 9. The vast majority of them died of yellow fever, making the epidemic in the city of 50,000 people one of the most severe in United States history. By the end of September, 20,000 people had fled the city. The mortality rate peaked in October, before frost finally killed the mosquitoes and brought an end to the epidemic in November. Doctors tried a variety of treatments, but knew neither
Yellow fever vaccine Foundation to improve the vaccine from the "Asibi" strain, discovered that a favorable chance mutation in the attenuated virus had produced a highly efficacious strain that was named 17D. After field trials in Brazil, over one million people were vaccinated by 1939, without severe complications. For his work on the yellow fever vaccine, Theiler received the 1951 Nobel Prize in Physiology or Medicine. Only the 17D vaccine remains in use today. The outbreak of yellow fever in Angola in January 2016 has raised concerns about whether the global supply of vaccine is adequate to meet the need during a large