流感病毒與流感疫苗 Influenza and Influenza Vaccines

InfluenzaandInfluenzaVaccines

Clinician’sOutreachandCommunicationActivity2007-2008SeasonInfluenzaHighlyinfectiousviralillness

Epidemicsreportedsince16thcentury

Virusfirstisolatedin1933InfluenzaVirusStrainsTypeA

moderatetosevereillnessallagegroupshumansandotheranimals

TypeBchangeslessrapidlythantypeAmilderepidemicshumansonlyprimarilyaffectschildrenNHSubtypesoftypeAdeterminedbyhemagglutinin(H)andneuraminidase(N)InfluenzaTypeASubtypesSurfaceAntigensandImmunityImmunityreduceslikelihoodofinfectionandseverityofdiseaseAntibodiesarespecifictodifferenttypesofsurfaceantigensChangesinHandNallowvirustoevadepreviouslydevelopedimmuneresponsesAntigenicchanges:driftandshiftInfluenzaAntigenicChangesAntigenicDriftMinorchange,samesubtypeCausedbypointmutationsingeneMayresultinepidemicExampleofantigenicdriftIn2003-2004,A/Fujian/411/2002-like(H3N2)viruswasdominantA/California/7/2004(H3N2)begantocirculateandbecamethedominantvirusin2005InfluenzaAntigenicChangesAntigenicShiftMajorchange,newsubtypeCausedbyexchangeofgenesegmentsMayresultinpandemicExampleofantigenicshiftH2N2viruscirculatedin1957-1967H3N2virusappearedin1968andcompletelyreplacedH2N2virusBurdenofInfluenza10%to20%ofthepopulationisinfectedwithinfluenzaviruseachyearAverageofmorethan200,000excesshospitalizationseachyearPersons65andolderand2yearsandyoungerathighestriskAverageof36,000deathseachyearPersons65andolderathighestriskofdeathInfluenzaAssociatedPulmonaryandCirculatoryDeaths,1998

AgeGroup(yrs)

Rate(per100,000)0–49 0.4–0.650–64 7.5

>65 98.3HospitalizationRatesforInfluenzaByAgeandRiskGroup*AgeGroup0-11mos1-2yrs3-4yrs5-14yrs15-44yrs45-64yrs>65yrsRate**

(high-risk)8084712319262318507Rate**

(nothigh-risk)2747239231622182*Datafromseveralstudies1972-2004*Hospitalizationsper100,000populationInfluenzaEpidemiologyReservoir Human,animals(typeAonly)

TransmissionRespiratory

Probablyairborne

TemporalpatternPeakDecember-Marchin temperatearea MayoccurearlierorlaterCommunicabilityMaximum1-2daysbeforeto 4-5daysafteronset InfluenzaSeasonalTrendsInfluenzaRegionalEpidemiologyInfluenzaVaccinesInactivatedsubunit(TIV)IntramuscularTrivalentAnnualLiveattenuatedvaccine(LAIV)IntranasalTrivalentAnnual InfluenzaVaccineSupplyManufacturer DosesProjected*GSK 30-35millionMedImmune 7millionNovartis 40millionsanofipasteur50millionCSL NoestimateprovidedTotal Upto127-132mInactivatedInfluenzaVaccinesAvailablein2007-2008VaccinePackageDoseAgeThimerosalFluzone(sanofipasteur)Multidosevial*Age-dependent>6mosYes

Singledosesyringe*0.25mL6-35mosNo

Singledosesyringe*0.5mL>36mosNo

Singledosevial*0.5mL>36mosNoFluvirin(Novartis)Multidosevial0.5mL>4yrsYesFluarix(GSK)Flulaval(GSK)SingledosesyringeMultidosevial0.5mL0.5mL>18yrs>18yrsTraceYes*inactivatedvaccinesapprovedforchildrenyoungerthan4yearsAfluria?

InfluenzaVaccineTrivalentinactivatedvaccineproducedinhen’seggsApprovedforpersons18yearsandolderAvailableinPreservative-freeprefilledsyringeMultidosevialSimilaradversereactionprofileasotherinactivatedinfluenzavaccinesWhyaYearlyInfluenzaVaccinationInfluenzavaccineexpiresJune30eachyearAntibodieswaneduringtheyearSurfaceantigensdriftandshift2007-2008InfluenzaVaccineA/Wisconsin/67/2005-like(H3N2)A/SolomonIslands/3/2006-like(H1N1)B/Malaysia/2506/2004-like(Victoria)InactivatedInfluenzaVaccineEfficacy70%-90%effectiveamonghealthypersons<65yearsofage30-40%effectiveamongfrailelderlypersons50%-60%effectiveinpreventinghospitalization80%effectiveinpreventingdeathLocalreactions 15%-20%Fever,malaise uncommonAllergicreactions rareNeurological veryrare

reactionsInactivatedInfluenzaVaccine

AdverseReactionsInactivatedInfluenzaVaccine

AdverseReactionsInactivatedinfluenzavaccinecontainsonlynoninfectiousfragmentsofinfluenzavirusInactivatedinfluenzavaccinecannotcauseinfluenzadiseaseTIVScheduleAgeGroup6-35mos3-8yrs9yrsandolderDose0.25mL0.50mL0.50mLNo.Doses1or2(4weekinterval)1or2(4weekinterval)1LAIVEfficacyAgainstlab-confirmedinfluenzafollowingexperimentalchallengeLAIV85%effectiveTIV71%effectiveNosignificantdifferenceNEJM2007LAIVmoreeffectiveinpreventingculture-confirmedinfluenzainchildrenyoungerthanfiveyearsLiveAttenuatedInfluenzaVaccine

AdverseReactionsChildrenNosignificantincreaseinURIsymptoms,fever,orothersystemicsymptomsIncreasedriskofasthmaorreactiveairwaysdiseaseinchildren12-59monthsofageAdultsIncreasedrateofcough,runnynose,nasalcongestion,sorethroat,andchillsreportedamongvaccinerecipientsNoincreaseintheoccurrenceoffeverNoseriousadversereactionsidentifiedLAIVIndicationsHealthy*persons5–49yearsofageClosecontactsofpersonsathighriskforcomplicationsofinfluenza(exceptseverelyimmunosuppressed)PersonswhowishtoreducetheirownriskofinfluenzaHealthcareworkers*PersonswhodonothavemedicalconditionsthatincreasetheirriskforcomplicationsofinfluenzaLAIVScheduleAgeGroup6mos–8years9yrsandolderDose0.2mL0.2mLNo.Doses1or2(4weekinterval)1TransmissionofLAIVVirusLAIVreplicatesintheNPmucosaMeansheddingofvirus7.6days–longerinchildrenOneinstanceoftransmissionofvaccinevirusdocumentedinadaycaresettingTransmittedvirusretainedattenuated,coldadapted,temperaturesensitivecharacteristicsTransmittedattenuatedvaccinevirusunlikelytocausetypicalinfluenzasymptomsUseofLAIVAmongHealthcarePersonnelNoinstancesoftransmissionofLAIVhavebeenreportedintheU.S.ACIPrecommendsthatLAIVcanbegiventoeligibleHCWsexceptthosethatcareforseverelyimmuno-suppressedpersons(hospitalizedandinisolation)NospecialprecautionsarerequiredforHCWswhoreceiveLAIVLAIVStorageMustbestoredat35-46degreesFahrenheitSimilartoTIVIfinadvertentlyfrozen,returntorefrigerator InfluenzaSeason2007-2008RecommendedGroupsforVaccinationChildren6-59monthsofageHealthyadults50yearsoldandolderPersons5–49yearsoldathighriskforcomplicationsPregnantwomenResidentsofnursinghomesHouseholdcontactsofpersonsathighriskforcomplicationsHealthcareworkersInfluenza:HighRiskforComplicationsBirththrough59monthsofageAdults50yearsoldandolderChroniclungdisease,asthmaChronicheartdiseaseMetabolicdiseases,e.g.diabetesChronicrenaldiseaseHighriskofaspirationImmunosuppressionPregnancyChronicaspirintherapy:18yearsoldandyoungerHIVInfectionandInactivatedInfluenzaVaccinePersonswithHIVathigherriskforcomplicationsofinfluenzaTIVinducesprotectiveantibodytitersinmanyHIV-infectedpersonsTransientincreaseinHIVreplicationreportedTIVwillbenefitmanyHIV-infectedpersonsPregnancyandInactivatedInfluenzaVaccineRiskofhospitalization4timeshigherthannonpregnantwomenRiskofcomplicationscomparabletononpregnantwomenwithhighriskmedicalconditionsVaccination(withTIV)recommendedforallwomenwhowillbepregnantduringtheinfluenzaseason,regardlessofgestationalageInfluenzaVaccine

Recommendations,2007-2008Immunizationprovidersshouldadministerinfluenzavaccinetoanypersonwhowishestoreducethelikelihoodofbecomingillwithinfluenzaortransmittinginfluenzatoothers*Healthypersons5-49yearsofage,includinghealthcarepersonnelmayreceiveeitherTIVorLAIVNewInfluenzaVaccineRecommendation2007-2008Children6monthsthrough8yearsbeingvaccinatedforthefirsttimeshouldreceiveTWOdosesSomechildrendonotreturnfortheseconddoseBeginningininfluenzaseason2007-2008ACIPandAAPwillrecommendthesechildrenreceiveTWOdosesthesecondvaccinationyearMMWR2007;56(RR-6)ThePrimingEffect1stdoseprimestheimmunesystem2nddosegeneratesspecificantibodyresponseIdealiffirstdosegiveninthefallLessidealiffirstdosegiveninSpring,especiallyifanewBstrainthefollowingAutumnSecondVaccinationSeasonDosesin1stseason12DosesthisSeason21MixandMatchIftwodosesareindicatedNonearecontraindicatedCanmixandmatchTIV/LAIVUseintervalofvaccinegivenfirstTheMagicofNinthBirthdayOnorafterninthbirthdayPrimingeffectcausedbynaturalinfectionthoughttobesignificantOnlyonedoseperseasonrequiredRegardlessofpreviousdosesInactivatedInfluenzaVaccine

ContraindicationsandPrecautionsContraindicationsSevereallergic