1. Hepatitis A and Hepatitis A Vaccine Epidemiology and Prevention of Vaccine- Preventable Diseases National Immunization Program Centers for Disease Control and Prevention Revised March 2002

2. Hepatitis A Epidemic jaundice described by Hippocrates Differentiated from hepatitis B in 1940s Serologic tests developed in 1970s Most commonly reported type of hepatitis in the United States

3. Hepatitis A Virus Picornavirus (RNA) Humans are only natural host Stable at low pH Inactivated by high temperature, formalin, chlorine

4. Hepatitis A Pathogenesis Entry into mouth Viral replication in the liver Virus present in blood and feces 10- 12 days after infection Virus excretion may continue for up to 3 weeks after onset of symptoms

5. Incubation period 28 days (range 15- 50 days) Illness not specific for hepatitis A Likelihood of symptomatic illness directly related to age Children generally asymptomatic, adults symptomatic Hepatitis A Clinical Features

6. Hepatitis A Epidemiology Reservoir Human. Endemic Transmission Fecal-oral Temporal pattern None Communicability2 weeks before to 1 week after onset

7. Source of Hepatitis A Infection

8. Hepatitis A – United States, 1966-2001* Vaccine Licensed *2001 provisional data

9. Hepatitis A Incidence* by Age Group *rate per 100,000 population. 1997 data.

10. Hepatitis A Incidence - United States and American Indians, 1990-2000 Source: National Notifiable Diseases Surveillance System, CDC American Indians United States Vaccine Licensed ACIP Recommendation

11. Inactivated whole virus HAVRIX (GlaxoSmithKline) VAQTA (Merck Vaccine Division) Pediatric and adult formulations Licensed for persons >2 years Hepatitis A Vaccines

12. Formulation Pediatric age dose Adult age dose HAVRIX 2-18 yrs 0.5 ml >18 yrs 1.0 ml VAQTA 2-18 yrs 0.5 ml >18 yrs 1.0 ml

13. Hepatitis A Vaccine Immunogenicity 95% seropositive after one dose 100% seropositive after two doses >97% seropositive after one 100% seropositive after 2 doses Adults Children (>2 years) and Adolescents

14. Hepatitis A Vaccine Efficacy 40,000 Thai children 4-15 years Vaccine efficacy 94% 1,000 children 2-16 years Vaccine efficacy 100% GlaxoSmithKline Merck

15. Hepatitis A Vaccines 1 dose Booster dose 6 - 18 months after first dose 1 dose Booster dose 6 - 18 months after first dose Adult Children and Adolescent

16. Children >2 years in states, counties, or communities where the average annual hepatitis A rate during 1987- 1997 was >20 per 100,000 population Hepatitis A Vaccine Recommendations Routine hepatitis A vaccination is recommended for:

17. Hepatitis A Vaccination Strategies High Incidence States One or more single age cohorts of children or adolescents Children in settings such as day care Children and adolescents in a wide range of ages in a variety of settings, such as when they seek health care for other purposes

18. Children >2 years in states, counties, or communities where the average annual hepatitis A rate during 1987- 1997 was 10 to 20 per 100,000 population Routine hepatitis A vaccination should be considered for: Hepatitis A Vaccine Recommendations

19. Hepatitis A Vaccination Strategies Intermediate Incidence States Statewide or community-based? Clustering of high-incidence areas within the state Feasibility Impact on incidence

20. Hepatitis A – High Incidence States

21. Twinrix Combination hepatitis B (adult dose) and hepatitis A vaccine (pediatric dose) Schedule: 0, 1, 6-12 months Approved for persons >18 years

22. International travelers Men who have sex with men Drug users Persons with occupational risk Persons with chronic liver disease, including hepatitis C Hepatitis A Vaccine Recommendations

23. Travelers to high or intermediate risk countries Protected by 4 weeks after dose Give concurrent IG for travel in <4 weeks Hepatitis A Vaccine Recommendations

24. Health care workers: not routinely recommended Day care centers: not routinely recommended Food handlers: may be considered based on local circumstances Hepatitis A Vaccine Recommendations

25. Hepatitis A Serologic Testing Not indicated for children May be considered for some adults and older adolescents Not indicated Prevaccination Postvaccination

26. Hepatitis A Vaccine Adverse Reactions Pain at injection site Systemic reactions uncommon No serious adverse events reported

27. Severe allergy to vaccine component or following prior dose Moderate or severe acute illness Hepatitis A Vaccine Contraindications and Precautions

28. National Immunization Program Hotline800.232.2522 Emailnipinfo@cdc.gov Websitewww.cdc.gov/nip