2016 Angola and DR Congo yellow fever outbreak case. Between 18 March and 22 April, the WHO was notified of 11 imported cases in China. Officials in Asia were concerned about the threat of yellow fever. On 28 March, ProMED-mail moderators Jack Woodall and Tom Yuill issued a strongly worded warning on the threat of yellow fever for countries that have endemic dengue fever (and thus the mosquito vector of yellow fever and dengue fever, Aedes aegypti), and particularly for countries in Asia, where until recently yellow fever has never appeared. Urban populations and mosquito-infested slums in Asia and Africa are much larger than in the past. A
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