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1、一、从鸡蛋中培养流感疫菌Moderntechnologyhasputmenonthemoonanddecipheredthehumangenome.Butwhenitcomestobrewingupflutomakevaccines,sciencestillturnstotheincredibleedibleegg.Eversincethe1940s,vaccinemakershavegrownlargebatchesofvirusinsidechickeneggs.Butgiventhatsome36,000Americansdieofflueachyear,it’sremarkablet
2、hatourfirstlineofdefenseisstillwhatSecretaryofHealthandHumanServicesTommyThompsoncalls“thecumbersomeandarchaicegg-basedproduction.”Newcell-basedtechnologiesareinthepipeline,however,andmayfinallygetthesupporttheyneednowthattheUnitedStatesisfacedwithacriticalshortageoffluvaccine.Althoughexpertsdisagr
3、eeonwhethernewwaysofproducingvaccinecouldhavepreventedashortageliketheonehappeningtoday,thereisnodoubtthattheexistingsystemhasseriousflaws.Eachyear,vaccinemanufacturersplaceadvanceordersformillionsofspeciallygrownchickeneggs.Meanwhile,public-healthofficialsmonitorcirculatingstrainsofflu,andeachMarc
4、htheyrecommendthreestrains—twoinfluenzaAstrainsandoneBstrain—formanufacturerstoincludeinvaccines.Inthelatespringandsummer,automatedmachinesinjectvirusintoeggsandlatersuckouttheinfluenza-richgoop.Virusfromtheeggs’innardsgetskilledandprocessedtoremoveeggproteinsandothercontaminantsbeforebeingpackaged
5、intovialsforfallshipment.Whyhasthiseggmethodpersistedforsixdecades?Themainreasonisthatit’sreliable.Buteventhoughtheeggsarereliable,theyhaveseriousdrawbacks.Oneisthelongleadtimeneededtoordertheeggs.Thatmeansit’shardtomakemorevaccineinahurry,incaseofashortageorunexpectedoutbreak.Andeggsmaysimplybetoo
6、cumbersometokeepupwiththehundredsofmillionsofdosesrequiredtohandlethedemandforfluvaccine.What’smore,someflustrainsdon’tgrowwellineggs.Lastyear,scientistswereunabletoincludetheFujianstraininthevaccineformulation.Itwasarelativelynewstrain,andmanufacturerssimplycouldn’tfindaquickwaytoadaptitsothatitgr
7、ewwellineggs.“Weknewthestrainwasoutthere,”recallsTheodoreEickhoffoftheUniversityofColoradoHealthSciencesCenter,“butpublic-healthofficialswereleftwithoutavaccine—and,consequently,amoreseverefluseason.”Worse,
