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 10 years. Although the WHO on 17 May 2013 advised that subsequent booster vaccinations are unnecessary, an older (than 10 years) certificate may not be acceptable at all border posts in all affected countries. A list of the countries that require yellow fever vaccination is published by the WHO. If the vaccination cannot be conducted for some reasons, dispensation may be possible. In this case, an exemption certificate issued by a WHO-approved vaccination center is required. Although 32 of 44 countries where yellow fever occurs endemically do have vaccination programmes, in many of these countries, less than 50% of their