1793 Philadelphia yellow fever epidemic with slaves, arrived from Cap Français, Saint-Domingue. The 2,000 immigrants were fleeing the slave revolution in the north of the island. They crowded the port of Philadelphia, where the first yellow fever epidemic in 30 years began in the city in August. It is likely that the refugees and ships carried the yellow fever virus and mosquitoes. It is transmitted during mosquito bites. The mosquitoes easily breed in small amounts of standing water. The medical community and others in 1793 did not understand the role of mosquitoes in the transmission of yellow fever and other diseases. Physicians and other survivors
Yellow fever vaccine group established in 2000 when a global shortage of yellow fever vaccine had developed because of the long lead time to manufacture the vaccine. As of 2013, there were four WHO-qualified manufacturers: Bio-Manguinhos in Brazil (with the Oswaldo Cruz Foundation), Institute Pasteur in Dakar, Senegal, the Federal State Unitary Enterprise of Chumakov Institute in Russia, and Sanofi Pasteur, the French pharmaceutical company. Two other manufacturers supply domestic markets: Wuhan Institute of Biological Products in China and Sanofi Pasteur in the United States. Seth Berkley, the chief executive of Gavi, has warned about the worldwide threat of yellow fever because of