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Moving towards universal varicella vaccination:the German experience
P. WutzlerJena, Germany
Friedrich Schiller University, Jena, GermanyInstitute of Virology and Antiviral Therapy
Current situation in Germany
Incidence of VZV infections per year: about 760,000 cases of varicella about 350,000 cases of zoster
Efficient and safe vaccines are available:
- Varilrix® (Oka, GlaxoSmithKline, on market since 1995)
- Varivax® (Oka, Sanofi Pasteur MSD, on market since 2004)
Unvaccinated 1215 yr-old adolescents without a history of varicella Seronegative staff in medical services as well as new staff at facilities for pre-school children Seronegative patients before or under immunosuppressive therapy or before organ transplantation Seronegative patients with leukaemia Susceptible patients with severe neurodermatitis Susceptible persons with close contact to the above mentioned groups Seronegative women attempting pregnancy
German recommendations for varicella vaccination until 2003/2004
(STIKO-Permanent Vaccination Commission)
Post-exposure: for use in susceptible persons (with contact to persons at risk) within 3 (5) days
Health economics project to calculate the clinical and cost-effectiveness of a
universal vaccination programme
Serological survey of the general population
Epidemiological study to evaluate the burden of disease for children, adolescents and adults (retrospective)
Assessment of the potential clinical and economic effects of a universal varicella vaccination programme versus no vaccination
development of a decision analysis model (tailored to Germany): EVITA (Economic Varicella Vaccination Tool for Analysis)
Wutzler et al. Med Microbiol Immunol 2002;191:89-96.Banz et al. Clin Microbiol Infect 2004;10:425-430.
VZV antibody prevalence in the German population
Months Years
0
10
20
30
40
50
60
70
80
90
100
Ser
op
osi
tive
(%
)
1-3
4-6
7-9
10-12
2-3
4-5
6-7
8-9
10-11
12-13
14-15
16-17
18-19
20-29
30-39
40-49
50-59
60-69
>=
70
Age groups
Comparison of VZV seroprevalence in different Europeancountries in relation to age(EuroVar, Summary of the 6th meeting, London, April 17-18, 2002)
Random sample selected from German telephone directory, stratified according to appropriate medical field,
letters written to physicians
PaediatricianGeneral
practitionerInternist
as family doctor
Telephone interview: 5 randomly selected varicella cases per practice, diagnosed in 1999
Retrospective study of basic epidemiological data to evaluate the burden of disease for all children,
adolescents and adults
Letters
Data from 1,334 unvaccinated patients from 232 practices
Epidemiological data Medical resource utilisation Working days lost by patient or by family
Basic epidemiological data
0 .0 0 0
0 .0 5 0
0 .1 0 0
0 .1 5 0
0 .2 0 0
0 .2 5 0
0 .3 0 0
2 6 1 0 1 4 1 8 2 2 2 6 3 0 3 4 3 8 4 2 4 6 5 0 5 4
A g e a t v a r ic e l la d ia g n o s is ( y e a r s )
R e la t iv e f r e q u e n c y o fin f e c t io n
16.3%
5.7% 0.8%
0.0%
5.0%
10.0%
15.0%
20.0%
Inci
den
ce r
ate
Severe course Complications Hospitalizations
Complications and severe courses
Basic epidemiological data
Projection of the frequency of varicella complications for Germany in 1999
Basis for projection: Prescription index, IMS 2000
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
Children Adolescents and adults
Bacterial superinfections Acute neurological disordersPneumonia & bronchitis Otitis mediaOthers
In Germany:
Every hour: 82 varicella cases!
Every day: 322 severe courses of varicella !
Every week: 744 complications!
Every month: 460 hospitalizations!
Every year: 21 deaths!
Varicella: a harmless childhood disease?
0
100.000
200.000
300.000
400.000
500.000
600.000
700.000
800.000
900.000
1.000.000
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Time in years
Var
icel
la c
ases
Children younger than 5 yrs
Children 610 years Adolescents 1115 yearsAdolescents 1620 years Adults older than 20 years
Varicella incidence over a timeframe of 30 years in anunvaccinated population
Vaccination strategies
Adolescent strategy: Vaccination of susceptible persons at the age of 1115 years
Children strategy : Universal vaccination of children at the age of 15 months
Combined strategy: Vaccination of children at the age of 15 months, and of
susceptible persons at the age of 1112 years
Potential clinical effects of varicella vaccination
Annual rates
No vaccination Adolescent Children Combined strategy strategy strategy
__________________________________________________________________________
Varicella cases 739,000 702,000 128,000 122,000
Total complications(any severity) 39,720 37,650 6,850 6,510
Major complications requiringhospitalization 5,740 5,300 1,000 940
Deaths 22 20 4 4
Potential clinical effects of varicella vaccination
Vaccination strategy
No immuni- Risk- General vaccination zation groups Basic Pessimistic Optimistic
Varicella cases 739,000 721,400 166,500 182,000 147,100
Total complications(any severity) 39,700 38,700 8,900 9,800 7,900
Major complications requiringhospitalization 5,740 5,520 1,290 1,420 1,140
Deaths 22 21 5 5 4
Basic case scenario: vaccination increases 11% to 85% within 8 yearsPessimistic case scenario : vaccination increases 5% to 85% within 9 yearsOptimistic case scenario : vaccination increases 22% to 85% within 7 years
Economic effects of varicella vaccination
Incremental costs (Mio Euro)
Vaccination strategiesAdolescents Children Combined
_____________________________________________________________ Soc. SF Soc. SF Soc.
SF
Direct costs +0.25 +0.38 +3.9 +4.3 +4.4 +4.7
Indirect costs - 8.43 - 0.52 - 55.2 -16.6 - 57.4 -16.8
Total - 8.18 - 0.14 - 51.3 -12.3 - 53.0 -12.0_________________________________________________________________ Benefitcost
ratio 8.44 1.13 4.12 1.75 4.10 1.70 _________________________________________________________________
Soc. Societal perspective, SF Sickness funds’ (payers’) perspective
12
14
16
18
20
22
24
26
28
75% 80% 85% 90% 95% 100%
Maximum vaccination coverage
Yea
rs
Children vaccination strategy Combined vaccination strategy
Time to eliminate varicella
Conclusions
Varicella causes a high burden of disease
Vaccination of children at the age of 15 months and additionally of adolescents at the age of 11 and 12 years:
– prevents approximately 80% of varicella cases and their complications per year
– eliminates varicella within an acceptable period.
Vaccination is effective regarding the reduction of the disease burden of varicella
Vaccination is effective regarding the reduction of the economic effects of varicella
Involved in the study were:
German Association for the Control of Virus Diseases (DVV) Varicella Vaccination Working Group
Institute of Medical Statistics and EpidemiologyTechnical University, Munich, Germany
Institute of Virology and Antiviral TherapyFriedrich-Schiller University, Jena, Germany
Outcomes International, Basle, Switzerland
GSK - Advisory Board on Varicella Vaccination GlaxoSmithKline, Munich, GermanyGlaxoSmithKline, Rixensart, Belgium
Robert Koch Institute, Berlin, Germany
July 2004
Varicella vaccination was included into the vaccination
schedule as standard vaccination
Universal varicella vaccination for all children preferably between the completed 11th14th month of age
Catch-up vaccination for all older children and adolescents without history of varicella (9 17 years)
Varicella vaccination - German recommendations(STIKO-Permanent Vaccination Commission, July, 2004)
9 – 175 – 615 2311 14432
Alter in voll. JahrenAlter in vollendeten Monaten
2.1. 3. 4.Sechsfach-Impfung
(Tetanus, Diphtherie, Keuchhusten, Hib, Polio, Hep.B)
1.MMR 2.MMR
Tetanus/Diphtherie
Tetanus/Diphtherie/
Keuchh./Polio
Vari-zellen
Goals of the new vaccination strategy against varicella
To reduce the rate of morbidity, complications, hospitalizations and mortality
To protect susceptible high-risk patients by herd immunity
To eliminate varicella in the long-term
To save medical and societal costs
Current situation Universal vaccination*Every hour: 82 varicella cases! 2 varicella cases!
Every day: 322 severe courses of 9 severe courses ofvaricella! varicella !
Every week: 744 complications! 21 complications!
Every month: 460 hospitalizations! 14 hospitalizations!
Every year: 21 deaths! 1 death!
*Annual average during the 2nd decade after implementation of universal vaccination
Universal varicella vaccination is very effective!