This document discusses the trends in chickenpox (varicella) in the USA before and after the introduction of the varicella vaccine in 1995. Before 1995, around 4 million people in the USA would get chickenpox each year, resulting in over 10,000 hospitalizations and 100-150 deaths annually. The varicella vaccine was found to be safe and effective based on data from other countries where it was already in use. Studies also found the vaccine to be cost-effective. After the vaccine was recommended for children in 1995, rates of chickenpox declined significantly, reducing medical costs and lost work days associated with the disease.

1. A dangerous trend in the USA
Pauline FLIPO
Mélanie TILTE 1
December 2nd, 2011

2. Headache
Fever
Blisters Tiredness
Itching
Chicken pox
Sore (Varicella)
throat
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http://www.cdc.gov

3. American parents’ first reaction
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4. USA - Before 1995
Each year
4 million people would get the
chicken pox
About 10,500 – 13,000 were
hospitalized Majority :
healthy
children and
100 to 150 died adults
http://www.cdc.gov 4
Walter A., Orenstein M.D., National Immunization Program. Overview of the US Vaccination Program

5. Why a VZV vaccine?
Varicella develops in nearly all persons living in the US
• > 90% of adults immune to VZV
Complications rate higher for persons ≥ 15 and < 1 years of age
• Bacterial infection of skins lesions, pneumonia, dehydratation, encephalitis, hepatitis
VZV vaccine licensed in several European countries (1984), Japan (1986), Korea (1988)
• No safety concerns after the administration of > 2 million doses in these countries
Varicella is less severe among vaccinated persons than unvaccinated persons
• Afebrile, fewer vesicular lesions, shorter duration of illness
Difference of incidence of herpes zoster
• 18 per 100000 persons/year for vaccinated people
• 77 per 100000 persons/year after natural Varicella
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MMWR, Advisory Committee on Immunization Practices (ACIP). Prevention of Varicella. July 12, 1996, Vol 45, No RR-11

6. Cost-effectiveness of a Routine Varicella
Vaccination program for US children
One dose/child under 6 30-year period following introduction
$35/dose At school entry, vaccination coverage level =
97% by the 6th year
Medical costs Work-loss costs
• Varicella treatment : Acyclovir • Parents missing work when their children
• Vaccinated people : no Acyclovir have the chickenpox ($201)
• Complications • Adults contracting chickenpox
Taking into account
• Evidence about vaccine efficacy
• Effects of expected changes in the age distribution of the disease
• Empirical data on the costs of medical utilization and work loss from varicella
6
Lieu, Tracy A et al. Cost-effectiveness of a Routine Varicella Vaccination program for US Children. JAMA; 1994; 271 (5), 375-381

7. Cost-effectiveness of a Routine Varicella
Vaccination program for US children
7
Lieu, Tracy A et al. Cost-effectiveness of a Routine Varicella Vaccination program for US Children. JAMA; 1994; 271 (5), 375-381

8. 88

9. 99

10. Recommendation map
Kg: Kindergarten 10
http://www.immunize.org/laws/vari_two.pdf Gr: School Grade

11. Effects of vaccination
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12. Effects of vaccination
Matthew M. Davis et al. Decline in varicella-related hospitalizations and expenditures for children and adults after introduction of 12
varicella vaccine in the United States. Pediatrics; 2004; 114; 785-792.

13. What about France?
● Herpes zoster prevention : insufficient data
● >15 years vaccinating 11 years old children necessary to avoid 1 death, 30 severe
complications and 30.000 cases
● Safety data : rash (injection site 1-4%, generalized 1-6%)
● Efficacy data : single-dose vaccination of children > 1 : not enough
● Fear : ↑ varicella among adolescents/adults and herpes zoster among the elderly
● Routine varicella vaccination not recommended for children > 1
● Recommended, if no varicella history :
- Vaccination within 3 days following exposure (adults & immunocompetent)
- Health care workers
- Contact with young children & immunodeficient people
- Children organ recipient
Conseil Supérieur d'Hygiène Publique de France – Section Maladies Transmissibles – Avis relatif à la vaccination contre la varicelle 13
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(19 mars 2004)

14. “Ils sont fous ces américains”
New drifts
Mailing infected clothes, saliva samples, infected lollipops...
Danger for workers of mailing companies
Risk of 20 years of imprisonment: under biohazard regulation (like anthrax)
Looking for more dangerous diseases :
Measles, mumps…
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15. Thanks for your attention
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