Yellow fever In 1873, Shreveport, Louisiana lost 759 citizens in an 80-day period to a Yellow fever epidemic, with over 400 additional victims eventually succumbing. The total death toll from August through November was approximately 1,200, In 1878, about 20,000 people died in a widespread epidemic in the Mississippi River Valley. That year, Memphis had an unusually large amount of rain, which led to an increase in the mosquito population. The result was a huge epidemic of yellow fever. The steamship "John D. Porter" took people fleeing Memphis northward in hopes of escaping the disease, but passengers were not allowed to disembark
Yellow fever vaccine vaccine, ten years after a primary dose, is not necessary. Since yellow fever vaccination began in the 1930s, only 12 known cases of yellow fever post-vaccination have been identified, after 600 million doses have been dispensed. Evidence showed that among this small number of "vaccine failures", all cases developed the disease within five years of vaccination. This demonstrates that immunity does not decrease with time. The World Health Organization recommends the vaccine between the ages of 9 and 12 months in areas where the disease is common. Anyone over the age of 9 months who has not been previously immunized