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 outbreaks, fractional dosing of the vaccine is being considered as a dose-sparing strategy to maximize limited vaccine supplies. Fractional dose yellow fever vaccination refers to administration of a reduced volume of vaccine dose, which has been reconstituted as per manufacturer recommendations. The first practical use of fractional dose yellow fever vaccination was in response to a large yellow fever outbreak in the Democratic Republic of the Congo in mid-2016. In March 2017, WHO launched a vaccination campaign in Brazil with 3.5 million doses from an emergency stockpile. In March 2017 the WHO recommended vaccination for travellers to certain parts of