........................................... PERSONTOUCHESASURFACETHATH
........................................... MSFROMINFLUENZACANHAPPENAT
romacold.influenzausuallycomesonsuddenlyand AYINCLUDETHESESYMPTOMS:FEV
hefeelssick.adultscancontinuetopassthefluvi USTOOTHERSFORANOTHERTHREET
useasoninthenorthernhemisphere).however,duriNGTHISTIME,OTHERRESPIRATOR
........................................... YOUHAVETHEFLUYOURRESPIRATO
achesthesesymptomsareusuallyreferredtoas-flu-LIKESYMPTOMS.-ANYONECANGE
anbeinfectedwiththefluvirusbuthavenosymptoms.DURINGTHISTIME,THOSEPERSO
........................................... DDRINKLOTSOFLIQUIDS,ANDTAK
achesthesesymptomsareusuallyreferredtoas-flu-LIKESYMPTOMS.-ANYONECANGE
geredbytheflu.foralistofgroupsthatareathighrISKFORCOMPLICATIONSFROMINF
hefeelssick.adultscancontinuetopassthefluvi USTOOTHERSFORANOTHERTHREET
anbeinfectedwiththefluvirusbuthavenosymptoms.DURINGTHISTIME,THOSEPERSO
ageofabout36,000peopleperyearintheunitedstatESDIEFROMINFLUENZA,AND114,
........................................... LDEVELOPLIFE-THREATENINGCO
........................................... OMPLICATIONSFROMINFLUENZA.
osevendaysaftersymptomsstart.childrencanpas THEVIRUSFORLONGERTHANSEVEN
........................................... YOUHAVETHEFLUYOURRESPIRATO
........................................... MSFROMINFLUENZACANHAPPENAT
anbeinfectedwiththefluvirusbuthavenosymptoms.DURINGTHISTIME,THOSEPERSO
achesthesesymptomsareusuallyreferredtoas-flu-LIKESYMPTOMS.-ANYONECANGE
erheadachetiredness(canbeextreme)drycoughsorETHROATNASALCONGESTIONBODY
torysymptoms,andyourillnessoccursduringnove BERTHROUGHAPRIL(THEUSUALFL
anbeinfectedwiththefluvirusbuthavenosymptoms.DURINGTHISTIME,THOSEPERSO
useasoninthenorthernhemisphere).however,duriNGTHISTIME,OTHERRESPIRATOR
........................................... OMPLICATIONSFROMINFLUENZA.
mplications(suchaspneumonia)asaresultofthef U.MILLIONSOFPEOPLEINTHEUNI
000peryearhavetobeadmittedtothehospitalasareSULTOFINFLUENZA.ANYONECANG
........................................... ENTERSTHEBODY.SOMEPERSONSC
........................................... LEMOSTPEOPLEWHOGETINFLUENZ
........................................... LEMOSTPEOPLEWHOGETINFLUENZ
........................................... OMPLICATIONSFROMINFLUENZA.
ng,ordiarrhea.thesesymptomscanbecausedbyman DIFFERENTVIRUSES,BACTERIA,
uenzaiscausedbyavirus,soantibiotics(likepen CILLIN)DON’TWORKTOCUREIT.T
........................................... ETINFLUENZAEACHYEAR.ANAVER
orefluseason.donotgiveaspirintoachildorteen GERWHOHASTHEFLUNEVERGIVEAS
emedicinesthatcontainnoaspirintorelievesymp OMS.THEMYTHOFTHE-STOMACHFL
........................................... ISARESPIRATORYDISEASEANDNO
chroniccongestiveheartfailuremayhaveworseni GOFTHISCONDITIONTHATISTRIG
........................................... ELIEVETHESYMPTOMSOFFLUINFL
........................................... LDEVELOPLIFE-THREATENINGCO
tisimpossibletotellforsureifyouhavetheflubasEDONSYMPTOMSALONE.DOCTORSC
........................................... LDEVELOPLIFE-THREATENINGCO
geredbytheflu.foralistofgroupsthatareathighrISKFORCOMPLICATIONSFROMINF
ewithasthmamayexperienceasthmaattackswhilet EYHAVETHEFLU,ANDPEOPLEWITH
........................................... ILLNESSESWITHNAUSEA,VOMITI
ryillnessmightbethefluifyouhavesuddenonseto BODYACHES,FEVER,ANDRESPIRA
useasoninthenorthernhemisphere).however,duriNGTHISTIME,OTHERRESPIRATOR
........................................... ELIEVETHESYMPTOMSOFFLUINFL
........................................... SCALLEDREYESYNDROME.CHILDR
orefluseason.donotgiveaspirintoachildorteen GERWHOHASTHEFLUNEVERGIVEAS
........................................... ISARESPIRATORYDISEASEANDNO
yillnessescancausesimilarsymptomsandflucanbeCAUGHTATANYTIMEOFTHEYEAR.I
........................................... CCINE(FLUSHOT)EACHFALL,BEF
........................................... ISARESPIRATORYDISEASEANDNO
mplications(suchaspneumonia)asaresultofthef U.MILLIONSOFPEOPLEINTHEUNI
ageofabout36,000peopleperyearintheunitedstatESDIEFROMINFLUENZA,AND114,
hefeelssick.adultscancontinuetopassthefluvi USTOOTHERSFORANOTHERTHREET
asfluvirusesonit_adoorhandle,forinstance_an THENTOUCHESHISORHERNOSEORM
uisspread,ortransmitted,whenapersonwhohasth FLUCOUGHS,SNEEZES,ORSPEAKS
romacold.influenzausuallycomesonsuddenlyand AYINCLUDETHESESYMPTOMS:FEV
pneumonia,bronchitis,andsinusandearinfectionSARETHREEEXAMPLESOFCOMPLIC
emedicinesthatcontainnoaspirintorelievesymp OMS.THEMYTHOFTHE-STOMACHFL
achesthesesymptomsareusuallyreferredtoas-flu-LIKESYMPTOMS.-ANYONECANGE
........................................... LEMOSTPEOPLEWHOGETINFLUENZ
anyage.peopleage65yearsandolder,peopleofany GEWITHCHRONICMEDICALCONDIT
anperformteststoseeifyouhavethefluifyouareinTHEFIRSTFEWDAYSOFYOURILLNE
erheadachetiredness(canbeextreme)drycoughsorETHROATNASALCONGESTIONBODY
emedicinesthatcontainnoaspirintorelievesymp OMS.THEMYTHOFTHE-STOMACHFL
........................................... CCINE(FLUSHOT)EACHFALL,BEF
........................................... ENTERSTHEBODY.SOMEPERSONSC
........................................... DDRINKLOTSOFLIQUIDS,ANDTAK
........................................... OMPLICATIONSFROMINFLUENZA.
erheadachetiredness(canbeextreme)drycoughsorETHROATNASALCONGESTIONBODY
anyage.peopleage65yearsandolder,peopleofany GEWITHCHRONICMEDICALCONDIT
........................................... LDEVELOPLIFE-THREATENINGCO
anbeinfectedwiththefluvirusbuthavenosymptoms.DURINGTHISTIME,THOSEPERSO
omach_cansometimesberelatedtotheflu_particulARLYINCHILDREN_THESEPROBLE
ewithasthmamayexperienceasthmaattackswhilet EYHAVETHEFLU,ANDPEOPLEWITH
........................................... ALETHEVIRUS.THEVIRUSENTERS
anyage.peopleage65yearsandolder,peopleofany GEWITHCHRONICMEDICALCONDIT
orefluseason.donotgiveaspirintoachildorteen GERWHOHASTHEFLUNEVERGIVEAS
thenose,throat,orlungsofapersonandbeginstomuLTIPLY,CAUSINGSYMPTOMSOFIN
kstherespiratorytractinhumans(nose,throat,anDLUNGS).THEFLUISDIFFERENTF
achesthesesymptomsareusuallyreferredtoas-flu-LIKESYMPTOMS.-ANYONECANGE
ewithasthmamayexperienceasthmaattackswhilet EYHAVETHEFLU,ANDPEOPLEWITH
orevenparasites.whilevomiting,diarrhea,andb INGNAUSEOUSOR_SICKTOYOURST
........................................... LEMOSTPEOPLEWHOGETINFLUENZ
osevendaysaftersymptomsstart.childrencanpas THEVIRUSFORLONGERTHANSEVEN
anperformteststoseeifyouhavethefluifyouareinTHEFIRSTFEWDAYSOFYOURILLNE
asfluvirusesonit_adoorhandle,forinstance_an THENTOUCHESHISORHERNOSEORM
chroniccongestiveheartfailuremayhaveworseni GOFTHISCONDITIONTHATISTRIG
erheadachetiredness(canbeextreme)drycoughsorETHROATNASALCONGESTIONBODY
........................................... DDRINKLOTSOFLIQUIDS,ANDTAK
pirintochildrenorteenagerswhohaveflu-likesymPTOMS_ANDPARTICULARLYFEVER
romacold.influenzausuallycomesonsuddenlyand AYINCLUDETHESESYMPTOMS:FEV
ryillnessmightbethefluifyouhavesuddenonseto BODYACHES,FEVER,ANDRESPIRA
anperformteststoseeifyouhavethefluifyouareinTHEFIRSTFEWDAYSOFYOURILLNE
ewithasthmamayexperienceasthmaattackswhilet EYHAVETHEFLU,ANDPEOPLEWITH
........................................... ISARESPIRATORYDISEASEANDNO
romacold.influenzausuallycomesonsuddenlyand AYINCLUDETHESESYMPTOMS:FEV
ageofabout36,000peopleperyearintheunitedstatESDIEFROMINFLUENZA,AND114,
yillnessescancausesimilarsymptomsandflucanbeCAUGHTATANYTIMEOFTHEYEAR.I
........................................... MSFROMINFLUENZACANHAPPENAT
orevenparasites.whilevomiting,diarrhea,andb INGNAUSEOUSOR_SICKTOYOURST
000peryearhavetobeadmittedtothehospitalasareSULTOFINFLUENZA.ANYONECANG
ewithasthmamayexperienceasthmaattackswhilet EYHAVETHEFLU,ANDPEOPLEWITH
achesthesesymptomsareusuallyreferredtoas-flu-LIKESYMPTOMS.-ANYONECANGE
chroniccongestiveheartfailuremayhaveworseni GOFTHISCONDITIONTHATISTRIG
tisimpossibletotellforsureifyouhavetheflubasEDONSYMPTOMSALONE.DOCTORSC
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
iscalled-antigenicdrift.-thesearesmallchangesinthevirusthathappenconti
YEAR.THEOTHERTYPEOFCHANGEISCALLED-ANTIGENICSHIFT.-ANTIGENICSHIFTISANAB
NGINGBYANTIGENICDRIFTALLTHETIME,ANTIGENICSHIFTHAPPENSONLYOCCASIONALLY.
RUPT,MAJORCHANGEINTHEINFLUENZAAVIRUSES,RESULTINGINNEWHEMAGGLUTININAND/
YEAR.THEOTHERTYPEOFCHANGEISCALLED-ANTIGENICSHIFT.-ANTIGENICSHIFTISANAB
A/Fujian/411/2002(H3N2)influenzavirusescanchangeintwodifferentways.one
YEAR.THEOTHERTYPEOFCHANGEISCALLED-ANTIGENICSHIFT.-ANTIGENICSHIFTISANAB
HAVELITTLEORNOPROTECTIONAGAINSTTHENEWVIRUS.WHILEINFLUENZAVIRUSESARECHA
HAVELITTLEORNOPROTECTIONAGAINSTTHENEWVIRUS.WHILEINFLUENZAVIRUSESARECHA
ornewhemagglutininandneuraminidaseproteinsininfluenzavirusesthatinfect
russtrainsappear,theantibodiesagainsttheolderstrainsnolongerrecognizet
GFLUVIRUSES.SO,PEOPLEWHOWANTTOBEPROTECTEDFROMFLUNEEDTOGETAFLUSHOTEVERY
russtrainsappear,theantibodiesagainsttheolderstrainsnolongerrecognizet
LECANGETTHEFLUMORETHANONETIME.INMOSTYEARS,ONEORTWOOFTHETHREEVIRUSSTRAI
IZEDBYTHEBODY’SIMMUNESYSTEM.THISPROCESSWORKSASFOLLOWS:APERSONINFECTEDW
typeavirusesundergobothkindsofchanges;influenzatypebviruseschangeonlyb
LECANGETTHEFLUMORETHANONETIME.INMOSTYEARS,ONEORTWOOFTHETHREEVIRUSSTRAI
NGINGBYANTIGENICDRIFTALLTHETIME,ANTIGENICSHIFTHAPPENSONLYOCCASIONALLY.
 

 
humans.shiftresultsinanewinfluenzaasubtype.whenshifthappens,mostpeople
he-newer-virus,andreinfectioncanoccur.thisisoneofthemainreasonswhypeop
NGINGBYANTIGENICDRIFTALLTHETIME,ANTIGENICSHIFTHAPPENSONLYOCCASIONALLY.
nsintheinfluenzavaccineareupdatedtokeepupwiththechangesinthecirculatin
iscalled-antigenicdrift.-thesearesmallchangesinthevirusthathappenconti
A/Fujian/411/2002(H3N2)influenzavirusescanchangeintwodifferentways.one
typeavirusesundergobothkindsofchanges;influenzatypebviruseschangeonlyb
NGINGBYANTIGENICDRIFTALLTHETIME,ANTIGENICSHIFTHAPPENSONLYOCCASIONALLY.
A/Fujian/411/2002(H3N2)influenzavirusescanchangeintwodifferentways.one
NUALLYOVERTIME.ANTIGENICDRIFTPRODUCESNEWVIRUSSTRAINSTHATMAYNOTBERECOGN
humans.shiftresultsinanewinfluenzaasubtype.whenshifthappens,mostpeople
GFLUVIRUSES.SO,PEOPLEWHOWANTTOBEPROTECTEDFROMFLUNEEDTOGETAFLUSHOTEVERY
YEAR.THEOTHERTYPEOFCHANGEISCALLED-ANTIGENICSHIFT.-ANTIGENICSHIFTISANAB
NGINGBYANTIGENICDRIFTALLTHETIME,ANTIGENICSHIFTHAPPENSONLYOCCASIONALLY.
NUALLYOVERTIME.ANTIGENICDRIFTPRODUCESNEWVIRUSSTRAINSTHATMAYNOTBERECOGN
iscalled-antigenicdrift.-thesearesmallchangesinthevirusthathappenconti
A/Fujian/411/2002(H3N2)influenzavirusescanchangeintwodifferentways.one
nsintheinfluenzavaccineareupdatedtokeepupwiththechangesinthecirculatin
humans.shiftresultsinanewinfluenzaasubtype.whenshifthappens,mostpeople
IZEDBYTHEBODY’SIMMUNESYSTEM.THISPROCESSWORKSASFOLLOWS:APERSONINFECTEDW
ithaparticularfluvirusstraindevelopsantibodyagainstthatvirus.asnewervi
RUPT,MAJORCHANGEINTHEINFLUENZAAVIRUSES,RESULTINGINNEWHEMAGGLUTININAND/
A/Fujian/411/2002(H3N2)influenzavirusescanchangeintwodifferentways.one
russtrainsappear,theantibodiesagainsttheolderstrainsnolongerrecognizet
YEAR.THEOTHERTYPEOFCHANGEISCALLED-ANTIGENICSHIFT.-ANTIGENICSHIFTISANAB
humans.shiftresultsinanewinfluenzaasubtype.whenshifthappens,mostpeople
NUALLYOVERTIME.ANTIGENICDRIFTPRODUCESNEWVIRUSSTRAINSTHATMAYNOTBERECOGN
LECANGETTHEFLUMORETHANONETIME.INMOSTYEARS,ONEORTWOOFTHETHREEVIRUSSTRAI
YTHEMOREGRADUALPROCESSOF.ANTIGENICDRIFT.....A/Fujian/411/2002(H3N2)PbN
NGINGBYANTIGENICDRIFTALLTHETIME,ANTIGENICSHIFTHAPPENSONLYOCCASIONALLY.
YEAR.THEOTHERTYPEOFCHANGEISCALLED-ANTIGENICSHIFT.-ANTIGENICSHIFTISANAB
LECANGETTHEFLUMORETHANONETIME.INMOSTYEARS,ONEORTWOOFTHETHREEVIRUSSTRAI
IZEDBYTHEBODY’SIMMUNESYSTEM.THISPROCESSWORKSASFOLLOWS:APERSONINFECTEDW
GFLUVIRUSES.SO,PEOPLEWHOWANTTOBEPROTECTEDFROMFLUNEEDTOGETAFLUSHOTEVERY
YTHEMOREGRADUALPROCESSOF.ANTIGENICDRIFT.....A/Fujian/411/2002(H3N2)PbN
nsintheinfluenzavaccineareupdatedtokeepupwiththechangesinthecirculatin
NUALLYOVERTIME.ANTIGENICDRIFTPRODUCESNEWVIRUSSTRAINSTHATMAYNOTBERECOGN
IZEDBYTHEBODY’SIMMUNESYSTEM.THISPROCESSWORKSASFOLLOWS:APERSONINFECTEDW
GFLUVIRUSES.SO,PEOPLEWHOWANTTOBEPROTECTEDFROMFLUNEEDTOGETAFLUSHOTEVERY
A/Fujian/411/2002(H3N2)influenzavirusescanchangeintwodifferentways.one
iscalled-antigenicdrift.-thesearesmallchangesinthevirusthathappenconti
nsintheinfluenzavaccineareupdatedtokeepupwiththechangesinthecirculatin
NUALLYOVERTIME.ANTIGENICDRIFTPRODUCESNEWVIRUSSTRAINSTHATMAYNOTBERECOGN
ithaparticularfluvirusstraindevelopsantibodyagainstthatvirus.asnewervi
NGINGBYANTIGENICDRIFTALLTHETIME,ANTIGENICSHIFTHAPPENSONLYOCCASIONALLY.
A/Fujian/411/2002(H3N2)influenzavirusescanchangeintwodifferentways.one
RUPT,MAJORCHANGEINTHEINFLUENZAAVIRUSES,RESULTINGINNEWHEMAGGLUTININAND/
A/Fujian/411/2002(H3N2)influenzavirusescanchangeintwodifferentways.one
he-newer-virus,andreinfectioncanoccur.thisisoneofthemainreasonswhypeop
YEAR.THEOTHERTYPEOFCHANGEISCALLED-ANTIGENICSHIFT.-ANTIGENICSHIFTISANAB
RUPT,MAJORCHANGEINTHEINFLUENZAAVIRUSES,RESULTINGINNEWHEMAGGLUTININAND/
ithaparticularfluvirusstraindevelopsantibodyagainstthatvirus.asnewervi
RUPT,MAJORCHANGEINTHEINFLUENZAAVIRUSES,RESULTINGINNEWHEMAGGLUTININAND/
ithaparticularfluvirusstraindevelopsantibodyagainstthatvirus.asnewervi
A/Fujian/411/2002(H3N2)influenzavirusescanchangeintwodifferentways.one
russtrainsappear,theantibodiesagainsttheolderstrainsnolongerrecognizet
NGINGBYANTIGENICDRIFTALLTHETIME,ANTIGENICSHIFTHAPPENSONLYOCCASIONALLY.
GFLUVIRUSES.SO,PEOPLEWHOWANTTOBEPROTECTEDFROMFLUNEEDTOGETAFLUSHOTEVERY
humans.shiftresultsinanewinfluenzaasubtype.whenshifthappens,mostpeople
HAVELITTLEORNOPROTECTIONAGAINSTTHENEWVIRUS.WHILEINFLUENZAVIRUSESARECHA
he-newer-virus,andreinfectioncanoccur.thisisoneofthemainreasonswhypeop
russtrainsappear,theantibodiesagainsttheolderstrainsnolongerrecognizet
IZEDBYTHEBODY’SIMMUNESYSTEM.THISPROCESSWORKSASFOLLOWS:APERSONINFECTEDW
HAVELITTLEORNOPROTECTIONAGAINSTTHENEWVIRUS.WHILEINFLUENZAVIRUSESARECHA
humans.shiftresultsinanewinfluenzaasubtype.whenshifthappens,mostpeople
IZEDBYTHEBODY’SIMMUNESYSTEM.THISPROCESSWORKSASFOLLOWS:APERSONINFECTEDW
nsintheinfluenzavaccineareupdatedtokeepupwiththechangesinthecirculatin
HAVELITTLEORNOPROTECTIONAGAINSTTHENEWVIRUS.WHILEINFLUENZAVIRUSESARECHA
NGINGBYANTIGENICDRIFTALLTHETIME,ANTIGENICSHIFTHAPPENSONLYOCCASIONALLY.
nsintheinfluenzavaccineareupdatedtokeepupwiththechangesinthecirculatin
NUALLYOVERTIME.ANTIGENICDRIFTPRODUCESNEWVIRUSSTRAINSTHATMAYNOTBERECOGN
nsintheinfluenzavaccineareupdatedtokeepupwiththechangesinthecirculatin
 

 
 
ornewhemagglutininandneuraminidaseproteinsininfluenzavirusesthatinfect
YTHEMOREGRADUALPROCESSOF.ANTIGENICDRIFT.....A/Fujian/411/2002(H3N2)PbN
humans.shiftresultsinanewinfluenzaasubtype.whenshifthappens,mostpeople
he-newer-virus,andreinfectioncanoccur.thisisoneofthemainreasonswhypeop