SkiptomaincontentHome#VaccinesworkThenextpandemicThenextpandemic:yellowfever?BacktoThenextpandemic:yellowfever?6April2021–by LindaGeddesandPriyaJoi6April2021–by LindaGeddesandPriyaJoi Inthe19thcentury yellowfeverhadtakenholdofpartsofEuropeandtheUSA,killingthousands.Nowmostlyaffecting AfricaandSouthAmerica,thismosquito-bornediseasecouldspreadatanymoment,threateningpublichealthandeconomicsecurityworldwide.InMarch2016,a32-year-oldChinesemansoughtmedicaltreatmentinBeijingforthefeverandchillshe’ddevelopedfivedaysearlier whileworkinginAngola.ThissouthernAfricancountrywasinthethroesofthebiggestoutbreakofyellowfevertheworldhadseenindecades.ThearrivalofthevirusinChina–thefirsteverconfirmedcaseofyellowfeverintheAsia-PacificRegion–sentachillupthespineofinfectiousdiseaseexpertsworldwide.Theyellowfevervirusisaflaviviruscloselyrelatedtothosethatcausedengue,Zikavirusdisease,JapaneseencephalitisandWestNilefever,butsignificantlymoredeadly.Sinceayellowfevervaccineexists,weareastepaheadofthevirus,butstoppingapotentialpandemicinitstrackswillrequirethepoliticalwillandfundingtoincreasevaccineavailabilityandrapiddeploymentinemergency.AroundtwobillionpeopleinAsianandPacificcountriesliveinareasoccupiedbytheAedesaegyptimosquito,whichtransmitsthedisease.Fewofthemhavehadanypreviousexposuretotheyellowfevervirus,andarenotroutinelyvaccinatedagainstit,meaningtheyhavenoimmunity.Hadthisman,oranyofhisteninfectedco-workers,arrivedduringBeijing’smosquitoseason– orflownintoanotherAsiancityfurthersouth–theconsequencescouldhavebeendire.TheimportationandspreadofyellowfevertotheAsia-Pacificregion"couldmaketheEbolaandZikaepidemicslooklikepicnicsinthepark,”warnedJohnWoodall,co-founderofthedisease-alertserviceProMED-mail.Onthisoccasion,therewasfortunatelynoonwardtransmission,buttheriskoffutureimportationandspreadofyellowfevervirusremainshigh.Overthecenturies,yellowfeverepidemicshavekilledthousandsofpeopleinEurope,USA,AfricaandtheAmericas,andhaltedmajorengineeringprojects,includingearlyFrenchattemptstobuildtheP