EpidemiologyEpidemiological FeaturesPrior to the use of vaccineAfter theuse of vaccineMorbidityMildepidemics:4009.5in1990(1/100000)Majorepidemics:500-1000Peak seasonInany time of a yearInwinterand springMajorepidemicsappearbyEpidemic cycledisappeared,Epidemiccycle2-4yr intervalsSporadiccasesincreasedAge6m-5y(98%<10y)Below6m and teenageTypicalcasesAtypical casessevere manifestationsmildmanifestationsClinicalless complicationsmore complicationsmanifestationshighmortalityrarely deathDivision Of Infectious Diseases And Gastroenterology
Prior to the use of vaccine After the use of vaccine Morbidity (1/100000) Mild epidemics: 400 Major epidemics: 500-1000 9.5 in1990 Peak season In winter and spring In any time of a year Epidemic cycle Major epidemics appear b y 2-4yr intervals Epidemic cycle disappeared, Sporadic c ases increased Age 6 m-5y (98%<10y) B e l o w 6 m and teenage Clinical manifestations Typical cases severe manifestations more complications high mortality Atypical cases mild manifestations less complications rarely death Epidemiology Epidemiological Features Division Of Infectious Diseases And Gastroenterology
EpidemiologyEpidemiological FeaturesPriortotheuse of vaccineAftertheuseofvaccineMajorepidemics:500-1000Morbidity9.5in1990Mildepidemics:400(1/100000)Peak seasonInany timeof a yearIn winter and springMajorepidemicsappearbyEpidemic cycledisappeared,Epidemiccycle2-4yr intervalsSporadiccasesincreasedAge6m-5y（98%<10y)Below6m and teenageTypical casesAtypical casessevere manifestationsmildmanifestationsClinicalless complicationsmore complicationsmanifestationshighmortalityrarelydeath?Division Of Infectious Diseases And Gastroenterology
Prior to the use of vaccine After the use of vaccine Morbidity (1/100000) Major epidemics: 500-1000 Mild epidemics: 400 9.5 in1 990 Peak season In winter and spring In any time of a year Epidemic cycle Major epidemics appear b y 2-4yr intervals Epidemic cycle disappeared, Sporadic c ases increased Age 6 m-5y (98%<10y) B e l o w 6 m and teenage Clinical manifestations Typical cases severe manifestations more complications high mortality Atypical cases mild manifestations less complications rarely death Epidemiology Epidemiological Features Division Of Infectious Diseases And Gastroenterology
EpidemiologyEpidemiological FeaturesPrior to the use of vaccineAftertheuse of vaccineMajorepidemics:500-1000Morbidity9.5 in1990Mild epidemics: 400(1/100000)Peak seasonInwinter and springInany time of a yearMajor epidemics appear byEpidemic cycle disappearedEpidemiccycle2-4yr intervalsSporadic cases increasedAge6m-5y (98%<10y)Below6m and teenageTypical casesAtypical casesseveremanifestationsmildmanifestationsClinicalmore complicationsless complicationsmanifestationshigh mortalityrarelydeathDivision Of Infectious Diseases And Gastroenterology
Prior to the use of vaccine After the use of vaccine Morbidity (1/100000) Major epidemics: 500-1000 Mild epidemics: 400 9.5 in1990 Peak season In winter and spring In any time of a year Epidemic cycle Major epidemics appear by 2-4yr intervals Epidemic cycle disappeared, Sporadic cases increased Age 6m-5y (98%<10y) B e low 6 m and teenage Clinical manifestations Typical c a ses severe manifestations more complications high mortality Atypical c a ses mild manifestations less complications rarely death Epidemiology Epidemiological Features Division Of Infectious Diseases And Gastroenterology
Epide miologyEpidemiological FeaturesPriortotheuse of vaccineAftertheuseofvaccineMajorepidemics:500-1000Morbidity9.5in1990Mildepidemics:400(1/100000)Peak seasonIn winterand springInany time of a yearMajorepidemicsappearbyEpidemic cycledisappeared,Epidemiccycle2-4yr intervalsSporadiccasesincreased6m-5y(98%<10y）AgeBelow6m and teenageTypicalcasesAtypical casesseveremanifestationsmildmanifestationsClinicalless complicationsmore complicationsmanifestationshighmortalityrarelydeathDivision Of Infectious Diseases And Gastroenterology
Prior to the use of vaccine After the use of vaccine Morbidity (1/100000) Major epidemics: 500-1000 Mild epidemics: 400 9.5 in1 990 Peak season In winter and spring In any time of a year Epidemic cycle Major epidemics appear b y 2-4yr intervals Epidemic cycle disappeared, Sporadic c ases increased Age 6m-5y (98%<10y) Below 6 m and teenage Clinical manifestations Typical cases severe manifestations more complications high mortality Atypical cases mild manifestations less complications rarely death Epidemiology Epidemiological Features Division Of Infectious Diseases And Gastroenterology
EpidemiologyVaccinerelatedepidemicVaccinationNatural InfectionWild strainLife-attenuated strainBoth antigenicity andBoth antigenicity andpathogenicity are declinedpathogenicity are strongThe antibody level is lowerThe antibody level is higherDivision Of Infectious Diseases And Gastroenterology
Vaccination Natural Infection Life-attenuated strain Wild strain Both antigenicity and pathogenicity are declined Both antigenicity and pathogenicity are strong The antibody level is lower The antibody level is higher Vaccine related epidemic Epidemiology Division Of Infectious Diseases And Gastroenterology