Yellow fever is an epidemic-prone mosquito-borne vaccine-preventable disease that is transmitted to humans by the bites of infected mosquitoes. Yellow fever is caused by an arbovirus (a virus transmitted by vectors such as mosquitoes, ticks, or other arthropods) transmitted to humans by the bites of infected Aedes and Haemagogus mosquitoes. These day-biting mosquitoes breed around houses (domestic), in forests or jungles (sylvatic), or both habitats (semi-domestic). Yellow fever is a high-impact high-threat disease, with a risk of international spread, which represents a potential threat to global health security.