Immunization免疫,免疫系统,全英版

IMMUNIZATIONImmunizationistheprocessofinducingimmunityagainstaspecificdisease.Immunitycanbeinducedeitherpassivelythroughadministrationofantibody-containingpreparationsoractivelybyadministeringavaccineortoxoidtostimulatetheimmunesystemtoproduceaprolongedhumoraland/orcellularimmuneresponse.IMMUNIZATIONItistheprocessofrenderingasubjectimmunebyinoculatingwithaspecificantigen.Itisthemethodofchoiceforpreventionofinfectiousdisease.GOALOFIMMUNIZATIONTheimmediategoalofimmunizationistopreventdiseaseinindividuals,buttheultimategoalistoeliminateoreveneradicateacommunicabledisease.Asaresultofeffectiveandsafevaccines,smallpoxhasbeeneradicated,polioisclosetoworldwideeradication,andmeaslesandrubellaarenolongerendemicintheU.S.IMMUNIZATIONActiveimmunityPassiveimmunityHerdimmunityACTIVEIMMUNITYActiveimmunizationinvolvesadministrationofallorpartofamicro-organisimormodifiedproductofthatmicro-organisim(eg.atoxoid,apurifiedantigen,oranantigenproducedbygeneticengineering)toevokeanimmunologicresponsemimickingthatofnaturalinfectionbutthatusuallypresentslittleornorisktotherecipient.PASSIVEIMMUNITYPassiveimmunizationentailsadministrationofpreformedantibodytoarecipient.Thisproducesimmediateprotection,whichonlylastsforsomeweeksormonths,untildonatedantibodiesarebrokendownorusedupbytheindividualHERDIMMUNITYHerdimmunityexistsifthenumberofpeopleinacommunitywhohaveactiveimmunityagainstaninfectionexceedsacriticallevel.Iftheselevelisachievedthenevennon-vaccinatedindividualsareprotectedfromgettingthedisease.Inthiswaytransmissionfallsorstopswithoutuniversalimmunity.VACCINEVaccinesaredefinedaswholeorpartsofmicroorganismsadministeredtopreventaninfectiousdisease.Thevaccineisusuallyaproteinsimilartopartofavirulentinfectiousorganismthatcanberecognizedbytheindividual’simmunesystem,whichthenproducesantibodiesorcellmediatedimmunityagainsttheantigeninthevaccine.TYPESOFVACCINELiveattenuatedvaccinesKilled,orinactivatedvaccinesConjugatedvaccinesToxoidvaccinesGeneticallyengineeredvaccinesLIVEATTENUATEDVACCINESLiveattenuatedvaccineisone,whichproducesactiveimmunitybycausingamildinfection.Avirulentorganismisweakenedsothatitproducesanantigenicresponsewithouttheseriousconsequencesofawildorganism.LIVEATTENUATEDVACCINESBCGPoliodropsMMRYellowfeverKILLED,ORINACTIVATEDVACCINESKilled,orinactivatedvaccineispreparedfromvirulentorganismsorpreformedantigeninactivatedbyheat,phenol,formaldehydeorsomeothermeans.KILLED,ORINACTIVATEDVACCINESPertussisCholeraInfluenzaInjectablepolioRabiesCONJUGATEDVACCINESTheresponsetopolysaccharidevaccineisincompleteandunreliableandconsequentlythesehavesometimesbeenconjugatedwithotherantigensinanattempttoimprovetheimmunologicalresponse.POLYSACCHARIDEVACCINESMeningococcalPneumococcalH.influenzaetypeb.TOXOIDVACCINESThesearetoxins,whichhavebeenrenderednon-toxicbytreatmentwithformaldehyde,buttheirantigenicityismaintained.TOXOIDVACCINESDiphtheriatoxoidsTetanustoxoidsAtoxoidisamodifiedbacterialtoxinthatismadenontoxicbutisstillabletoinduceanactiveimmuneresponseagainstthetoxinGENETICALLYENGINEEREDVACCINESHepatitisBVaccinedevelopmentandtesting.MorbidityandMortalityWeeklyReport(MMWR).AmericanAcademyofFamilyPhysicians(AAFP)VACCINATIONSCHEDULEThefollowingsarethecommoninfectiousdiseasesagainstwhichworldhealthorganization(WHO)recommendsroutineimmunization.TuberculosisDiphtheriaPertusisTetanusPolioMeaslesHepatitisB.EXPANDEDPROGRAMMEONIMMUNIZATION(EPI)AgeVaccineDoseRouteAtbirthBCGOPV00.05ml2dropsI/D(Rt.Deltoid)Oral6weeksDPT1OPV1HBV10.5ml2drops0.5mlI/MOralI/M10weeksDPT2OPV2HBV20.5ml2drops0.5mlI/MOralI/M14weeksDPT3OPV3HBV30.5ml2drops0.5mlI/MOralI/MEXPANDEDPROGRAMMEONIMMUNIZATION(EPI)AgeyearsVaccineDoseRoute9monthsMeasles0.5mls/c15monthsMMR0.5mls/c18monthsDPTboosterOPVbooster0.5ml2dropsI/MOral5yearsDTboosterOPVbooster0.5ml2dropsI/MOral10yearsTdbooster0.5mlI/MVACCINATIONSCHEDULE

PREGNANTWOMENPregnantwomen(pregnancy4th-8thmo)TT1&TT2atonemothinterval(1stpregnancy)TTonedose(subsequentpregnancy;ifwithin5yr)TTtwodoses(subsequentpregnancy;ifbeyond5yr)VACCINATIONSCHEDULE

GENERALWOMENGeneralwomen(age15-49)TT-1atanyageTT-2afteronemonthTT-3after6monthTT-4after1yrTT-5after5yrPRECAUTIONSANDRECOMMENDATIONSLivevaccinesshouldnotbeadministeredtochildrenwithimmuno-deficiencydisease.Injectionshouldbegivenintothelateralthighorintothedeltoid.Deepinjectionandmassagereducestheincidenceofantigeniccysts.DPTinjectionmaycausemildfeverwithin12-24hoursanditisnotacontraindicationforfurtherimmunization.PRECAUTIONSANDRECOMMENDATIONSIfconvulsionsoccurwithin72hoursofDPTinjectionfurtheradministrationofpertussisvaccineiscontra-indicated.ThengiveDTaloneAfter2yearsofagechildrenshouldnotreceivepertussisvaccine.Childrenwithbraindamageorprevioushistoryofconvulsionshouldnotreceivepertussisvaccine.Incaseofhighriskduetocontactwithacaseofpertussis,DPTcanbeinitiatedat2weekofage.Intheeventofanepidemicorhighrisk,measlesvaccinecanbegivenat6monthsage.PRECAUTIONSANDRECOMMENDATIONSImmunizationshouldbedelayedonlyincaseofillnesswithhighfever,sothatanysignoftheillnesswillnotattributedtothevaccination.Administrationofaliveattenuatedvaccinesshouldbedelayedforatleastsixweekswhenarecentinjectionofpolyvalentimmuneglobulinhasbeengiven.CONDITIONS,WHICHARENOTCONTRA-INDICATEDTOIMMUNIZATIONMinorillnesssuchasupperrespiratorytractinfectionsordiarrhea,withfever<38.5ºC.Allergy,asthma,orotheratopicmanifestations.Prematurity,smallfordateinfants.MalnutritionFamilyhistoryofconvulsionsTreatmentwithantibiotics,lowdosecorticosteroidsorlocallyactingsteroids.CONDITIONS,WHICHARENOTCONTRA-INDICATEDTOIMMUNIZATIONDermatitis,eczema,orlocalizedskininfections.Chronicdiseasesoftheheart,lung,kidneyandliver.StableneurologicalconditionssuchascerebralpalsyandDownsyndrome.Historyofjaundiceafterbirth.BCGVACCINEBacilleCalmetteGuerin(BCG)isthemostwidelyusedvaccineBCGismadeofalive,weakened(attenuated)strainofmycobacteriumbovisIdealageforvaccinationisthenewbornperiod(1stweek)ifnotgivenatbirththenat6weeksItiseffectiveinreducingthelikelihoodandseverityofTBininfantsandyoungchildren.VACCINEDOSEItisgivenintra-dermallyinadoseof0.05mlfornewbornsand0.1mlforallotherchildrenVACCINEEFFICACY0-80%forTBlung75-86%formeningitisandmiliarytuberculosis.Durationofimmunityunknownbutsomeevidencethatduration10-15yrs.COURSEOFBCGThewhealofinjectiondisappearsin30minutesTwotothreeweekslateranoduleformswhichindurateandformsasuperficialabscess,itulceratesandhealsin4-6weeks.Thewholeprocessiscompletedin2monthsandleavesascar.COMPLICATIONSOFBCGKoch’sphenomenoni.e.,acceleratedreactionwhichcompletesinabout10daysErythemanodosumDeepabscessandulcerationLymphadenopathyofsupra-clavicularoraxillarynodesGeneralizedtuberculosis.POLIOMYELITISVACCINEVaccineavailableagainstpoliomyelitisare:Liveattenuatedoralpoliovirusvaccine(OPV,Sabin)[ContainattenuatedpoliovirusI,IIandIII]Injectablepoliovirusvaccine(IPV,Salk)VACCINEEFFICACY>90%inindustrializedcountries72-98%inhotclimatesLowerprotectionagainsttype3LifelongimmunityafterboosterdoseADVANTAGEOFOPVItiseasytoadministerIthassuperiorantibodyresponseProvidesrapidimmunitywithin1weekProvidesherdimmunitySIDEEFFECTOFOPVParalyticpolioinimmunizedchild(1:6million)CONTRA-INDICATIONOFOPVInfectionwithHIVKnownimmunedeficiencyTETANUSIMMUNIZATIONActiveimmunizationPassiveimmunizationACTIVEIMMUNIZATIONActiveimmunization:TetanustoxoidTetanustoxoid(TT)ispreparedbyinactivatingthetoxinwithformaldehyde.NewbornscanbeprotectedfromtetanusifmotherisactivelyimmunizedduringpregnancyDOSEOFTOXOIDVaccineisadministeredintra-muscularlyinadoseof0.5mlTwo0.5mldoseI/Mat4-8weeksintervalThirddoseafter1yrBoosterdoseafter5-10yrsPASSIVEIMMUNIZATIONPassiveimmunization:Tetanusimmunoglobulin(TIG)ItisusedforprophylaxisandtherapyProvidesprotectionfor30daysProphylacticdoseis250IUI/MTherapeuticdoseis1000-10000IU,I/MTETANUSANTITOXIN(ATS)Tetanusantitoxin(ATS)Protectionlastfor7-15daysProphylacticdoseis1500-3000IU,I/MTherapeuticdoseinneonates10000I/MTherapeuticdoseinchildren40000-60000IU(halfI/M,halfI/V)HEPATITISBVACCINERoutinevaccinationisgiventoallinfants,childrenandadolescentsHEPATITISBVACCINEDOSEDoseofvaccineis0.5mlifageislessthan19yrsDoseis1mlifageismorethan19yrsOptimally,threeI/MdosesofhepatitisBvaccineareneeded,schedule,0,1,and6moths.HepatitisBvaccineshouldbegivenonlyinthedeltoidmuscleforadolescentsandchildren,andintheantero-lateralthighmuscleforinfantsandneonantsHEPATITISBVACCINEInfantborntoHBsAgpositivemothers:InfantborntoHBsAgpositivemothersshouldreceive0.5mlofhepatitisBimmuneglobulin(HBIG)within12hoursafterbirth,andhepatitisBvaccineataseparatesite.Theseconddoseofvaccineisrecommendedatage1-2monthsandthirddoseatage6month.At12-15monthsofageimmunizedinfantsshouldbetestedforantibodytoHBsAg(ant-HBs),ifanti-HBsispositive,vaccinationhasbeeneffective.Ifnegativeimmunizationhasfailedandtheinfantisachroniccarrier.HAEMOPHILIUSINFLUENZAETYPEBVACCINEH.influenzaetypeb(Hib)isacommoncauseofbacterialmeningitisandvarietyofseriousandpotentiallylifethreateninginfectious,includingpneumonia,epiglottitisandsepsisininfantsandolderchildrenItisadaptedtotheroutinescheduleandgiventogetherwithDPT,aswellasaboosterdoseat18months.Olderchildrenandadultsrequireonly1dose.OTHERS

PneumococcalvaccinesTyphoidvaccineCholeravaccineRabiesimmunizationPNEUMOCOCCALVACCINESStreptococcuspneumoniaeisresponsibleforthreetypesofdiseases,pneumonia,otitisandmeningitis.Itistheleadingcauseofseverepneumoniainchildrenunder5yearsage.ThecurrentvaccineagainstS.pneumoniaeiscomposedofcapsularantigento7,9or23serotypes.(dose0.5mlIMorSC)Recommendationsaretoagivedoseofvaccinetochildrenover2yearsofoldwhoarehighrisk(sicklecelldisease,chronicrenalfailure,immunosupressionfromorgantransplantationandHIVinfection)Thevaccineisoflimitedefficacyinchildrenunder2yearsofage.TYPHOIDVACCINEInmostendemicareastheincidenceoftyphoidfeverishighestinchildren5-19yearsofage;henceavaccineisneededthatcanestablishdurableimmunitypriortoschoolage.PurifiedViantigenisusedasaonedoseinjectablevaccineThedoseofViisasingleintramusculard