# Presentation: 397174

## Hepatitis A and Hepatitis A Vaccine

**Epidemiology and Prevention of Vaccine-Preventable Diseases**
**National Immunization Program**
**Centers for Disease Control and Prevention**

**Revised January 2007**

## NOTICEContent and order of the slides in this file may differ from those presented on the  broadcast and webcast

## Hepatitis A Virus

**Picornavirus (RNA)**
**Humans are only natural host**
**Stable at low pH**
**Inactivated by high temperature (185****°****F or higher), formalin, chlorine**

## Hepatitis A Clinical Features

**Incubation period 28 days    (range 15-50 days)**
**Illness not specific for hepatitis A**
**Likelihood of symptomatic illness directly related to age**
**Children <6 years generally asymptomatic; adults usually symptomatic**

## Hepatitis A Epidemiology

**Reservoir****	****	**** ****	****Human**** **
**Transmission****	**** ****	****Fecal-oral**
**Temporal pattern  ****	****None **** **
**Communicability****	****2 weeks before to ****	****	****	****	****	****1 week after onset**

## Hepatitis A—United States, 1990-2000

**Hepatitis A—United States, 1990-2000**
**Risk Factors**

**Source:  NNDSS/VHSP**

**Notes:**
From 1990 through 2000, the most frequently reported source of infection was personal contact (household or sex) with an infected person (14%).  Two percent of cases involved a child or employee in day-care; 6% of cases were a contact of a child or employee in day-care; 5% of cases reported recent international travel; and 4% of cases reported being part of a recognized foodborne outbreak. Injection drug use was a reported risk factor in 6% of cases; men who have sex with men represented 10% of cases.  Forty-six percent of reported hepatitis A cases could not identify a risk factor for their infection. 
Note: Risk factor percentages rounded to nearest percent

## Hepatitis A - United States, 1966-2006*

**Hepatitis A - United States, 1966-2006***

**Year**

***2006 provisional total**

## Hepatitis A Incidence, 1997 

**Hepatitis A Incidence, 1997 **

***rate per 100,000 population**

**Notes:**
This graph shows the incidence of reported hepatitis A by age group in 1997.  The rates are expressed as cases per 100,000 population.  The highest incidence of hepatitis A infection was among children 5 to 14 years of age.  This age group accounted for about 18% of reported cases.  Notice that the incidence of reported hepatitis in children younger than 5 years of age was substantially less than in older children.  Cases in this age group are under-reported because most infections in young children are asymptomatic.

Since 1997, rates among children have declined more rapidly than among adults and in 2001...

## Hepatitis A
High and Intermediate Incidence States, 1999

**High and Intermediate Incidence States, 1999**

**Notes:**
The 6 states in this category are shown in orange.  These states accounted for about 12% of the US population and 18% of reported hepatitis A cases during 1987 through 1997.  Each of the lower incidence states (in blue) should decide whether to adopt a statewide or a community-based vaccination strategy.

## Hepatitis A Incidence By Vaccination Recommendation Status 1990-2004

**Year**

## Hepatitis A Vaccines

**Inactivated whole virus**
**HAVRIX  (GlaxoSmithKline)**
**VAQTA (Merck)**
**Pediatric and adult formulations**
**Approved for persons 12 months of age and older**

## Hepatitis A Vaccine Immunogenicity

**Adults**
**>95% seropositive after one dose**
**100% seropositive after two doses**** **
**Children (**_**>**_**12 months) and Adolescents**
**>97% seropositive after one**
**100% seropositive after 2 doses**

## Hepatitis A Vaccines

**Adult**
**1 dose**
**booster dose 6-18 months after first dose**
**Children and Adolescent**
**1 dose**
**booster dose 6-18 months after first dose**

## Hepatitis A VaccineMinimum Interval

**The minimum interval between the first and booster doses of hepatitis A vaccine is six calendar months **

## All children should receive hepatitis A vaccine at 12-23 months of age
Vaccination should be integrated into the routine childhood vaccination schedule
Children who are not vaccinated by 2 years of age can be vaccinated at subsequent visits 

**Vaccination should be integrated into the routine childhood vaccination schedule**
**Children who are not vaccinated by 2 years of age can be vaccinated at subsequent visits **

***MMWR***** 2006;55(RR-7):1-23**

**Hepatitis A Vaccine Recommendations**

## Hepatitis A Vaccine Recommendations

**In areas with an existing hepatitis A vaccination program for children 2-18 years of age**
**these programs should be maintained**
**new efforts focused on routine      vaccination of children 12 months of age should enhance, not replace ongoing vaccination programs**
**In areas without an existing hepatitis A vaccination program, catch-up vaccination of unvaccinated children 2-18 years of age can be considered **

***MMWR***** 2006;55(RR-7):1-23**

## Hepatitis A VaccineRecommendations

**International travelers**
**Men who have sex with men**
**Persons who use illegal drugs**
**Persons with occupational risk**
**Persons with chronic liver disease**

## Hepatitis A VaccineInternational Travel

**Protection following hepatitis A vaccine might not be complete until 4 weeks after vaccination**
**For optimal protection immune globulin also may be administered to persons traveling to a high-risk area <4 weeks after the first dose of vaccine **
**Children younger than 12 months of age should receive IG prior to travel to high-risk area **

## Twinrix

**Combination hepatitis B (adult dose) and hepatitis A vaccine (pediatric dose)**
**3 dose schedule at 0, 1, 6-12 months**
**Approved only for persons 18 years of age and older**

## Schedules That Include BothTwinrix and Hepatitis A Vaccine

**Adult formulation single antigen hepatitis A vaccine may be used to complete a schedule begun with Twinrix and vice versa***
**Acceptable schedules**
**2 Twinrix and 1 hepatitis A (adult formulation**
**1 Twinrix and 2 hepatitis A (adult formulation)**
**Maintain spacing recommended for Twinrix**

***for persons 19 years of age or older**

## Healthcare workers: not routinely recommended
Child care centers: not routinely recommended
Sewer workers or plumbers:  not routinely recommended
Food handlers: may be considered based on local circumstances

**Child care centers: not routinely recommended**
**Sewer workers or plumbers:  not routinely recommended**
**Food handlers: may be considered based on local circumstances**

**Hepatitis A Vaccine****Recommendations**

## Hepatitis A VaccineAdverse Reactions

**Local reactions**
**Systemic reactions**
**   ****(malaise, fatigue, low grade fever)**
**No serious adverse reactions reported**

**20%-50%**
**<10%**

## Hepatitis A VaccineContraindications and Precautions

**Severe allergic reaction to a vaccine component or following a prior dose**
**Moderate or severe acute illness**** **

## National Immunization ProgramContact Information

**Telephone****	****	****800.CDC.INFO**** **
**Email****	****	****	****nipinfo@cdc.gov**** **
**Website****	****	****www.cdc.gov/nip**