How are hepatitis A vaccines made?
There is no live virus in hepatitis A vaccines. The virus is inactivated during production of the vaccines, similar to Salk-type inactivated polio vaccine.
How long does hepatitis A vaccine protect you?
Although data on long-term protection are limited, estimates based on modeling techniques suggest that protection will last for at least 20 years.
When are persons protected after receiving hepatitis A vaccine?
Protection against hepatitis A begins four weeks after the first dose of hepatitis A vaccine.
Can hepatitis A vaccine be given after exposure to hepatitis A virus?
No, hepatitis A vaccine is not licensed for use after exposure to hepatitis A virus. In this situation, immune globulin should be used.
Should prevaccination testing be done?
Prevaccination testing is done only in specific instances to control cost (e.g., persons who were likely to have had hepatitis A in the past). This includes persons who were born in countries with high levels of hepatitis A virus infection, elderly persons, and persons who have clotting factor disorders and may have received factor concentrates in the past.
Should postvaccination testing be done?
No.
Can hepatitis A vaccine be given during pregnancy or lactation?
We don't know for sure, but because vaccine is produced from inactivated hepatitis A virus, the theoretical risk to the developing fetus is expected to be low. The risk associated with vaccination, however, should be weighed against the risk for hepatitis A in women who may be at high risk for exposure to hepatitis A virus.
Can hepatitis A vaccine be given to immunocompromised persons? (e.g., persons on hemodialysis or persons with AIDS)
Yes.
What is Twinrix®?
It is a combined hepatitis A and hepatitis B vaccine for use in persons aged 18 years and older. Primary vaccination consists of three doses, given on a 0-, 1-, and 6-month schedule, the same schedule as that used for hepatitis B vaccine alone.
Read more about hepatitis A and hepatitis B vaccine schedules.
Read more about hepatitis B vaccine.
Immune Globulin
What is immune globulin?
Immune globulin is a preparation of antibodies that can be given before exposure for short-term protection against hepatitis A and for persons who have already been exposed to hepatitis A virus. Immune globulin must be given within 2 weeks after exposure to hepatitis A virus for maximum protection.
Is immune globulin safe?
Yes. No instance of transmission of HIV (the virus that causes AIDS) or other viruses has been observed with the use of immune globulin administered by the intramuscular route. Immune globulin can be administered during pregnancy and breast-feeding.
Is immune globulin in short supply?
Please click here for immune globulin status.
Who Should Get Vaccinated Against Hepatitis A?
Hepatitis A vaccination provides protection before one is exposed to hepatitis A virus. Hepatitis A vaccination is recommended for the following groups who are at increased risk for infection and for any person wishing to obtain immunity.
Persons traveling to or working in countries that have high or intermediate rates of hepatitis A.
All susceptible persons traveling to or working in countries that have high or intermediate rates of hepatitis A should be vaccinated or receive immune globulin before traveling. Persons from developed countries who travel to developing countries are at high risk for hepatitis A. Such persons include tourists, military personnel, missionaries, and others who work or study abroad in countries that have high or intermediate levels of hepatitis A. The risk for hepatitis A exists even for travelers to urban areas, those who stay in luxury hotels, and those who report that they have good hygiene and that they are careful about what they drink and eat.
Children in states, counties, and communities where rates of hepatitis A were/are at least twice the national average during the baseline period of 1987-1997.
Children living in states, counties, and communities where rates of hepatitis A are at least twice the national average (> 20 cases/1,000,000) in baseline period should be routinely vaccinated beginning at 2 years of age. High rates of hepatitis A have been found in these populations, both in urban and rural settings. In addition, to effectively prevent epidemics of hepatitis A, vaccination of previously unvaccinated older children is recommended within 5 years of initiation of routine childhood vaccination programs. Although rates differ among areas, available data indicate that a reasonable cutoff age in many areas is 10-15 years of age because older persons have often already had hepatitis A. Vaccination of children before they enter school should receive highest priority, followed by vaccination of older children who have not been vaccinated.
Men who have sex with men
Sexually active men (both adolescents and adults) who have sex with men should be vaccinated.
Hepatitis A outbreaks among men who have sex with men have been reported frequently. Recent outbreaks have occurred in urban areas in the United States, Canada, and Australia.
Illegal-drug users
Vaccination is recommended for injecting and noninjecting illegal-drug users.
Persons who have occupational risk for infection
Persons who work with hepatitis A virus-infected primates or with hepatitis A virus in a research laboratory setting should be vaccinated. No other groups have been shown to be at increased risk for hepatitis A virus infection because of occupational exposure.
Outbreaks of hepatitis A have been reported among persons working with non-human primates that are susceptible to hepatitis A virus infection, including several Old World and New World species. Primates that were infected were those that had been born in the wild, not those that had been born and raised in captivity.
Persons who have chronic liver disease
Persons with chronic liver disease who have never had hepatitis A should be vaccinated, as there is a higher rate of fulminant (rapid onset of liver failure, often leading to death) hepatitis A among persons with chronic liver disease. Persons who are either awaiting or have received liver transplants also should be vaccinated.
Persons who have clotting-factor disorders
Persons who have never had hepatitis A and who are administered clotting-factor concentrates, especially solvent detergent-treated preparations, should be given hepatitis A vaccine.
All persons with hemophilia (Factor VIII, Factor IX) who receive replacement therapy should be vaccinated because there appears to be an increased risk of transmission from clotting-factor concentrates that are not heat inactivated.
Which Groups Do Not Routinely Need Hepatitis A Vaccine?
Food service workers
Foodborne hepatitis A outbreaks are relatively uncommon in the United States; however, when they occur, intensive public health efforts are required for their control.
Although persons who work as food handlers have a critical role in common-source foodborne outbreaks, they are not at increased risk for hepatitis A because of their occupation. Consideration may be given to vaccination of employees who work in areas where community-wide outbreaks are occurring and where state and local health authorities or private employers determine that such vaccination is cost-effective.
Sewerage workers
In the United States, no work-related outbreaks of hepatitis A have been reported among workers exposed to sewage.
Health-care workers
Health-care workers are not at increased risk for hepatitis A. If a patient with hepatitis A is admitted to the hospital, routine infection control precautions will prevent transmission to hospital staff.
Children under 2 years of age
Because of the limited experience with hepatitis A vaccination among children under 2 years of age, the vaccine is not currently licensed for this age-group.
Day-care attendees
The frequency of outbreaks of hepatitis A is not high enough in this setting to warrant routine hepatitis A vaccination. In some communities, however, day-care centers play a role in sustaining community-wide outbreaks. In this situation, consideration should be given to adding hepatitis A vaccine to the prevention plan for children and staff in the involved center(s).
Residents of institutions for developmentally disabled persons
Historically, hepatitis A virus infections were common among persons with developmental disabilities living in institutions. Currently, the occurrence of hepatitis A virus infections have diminished.
International Travel
(the following map gives prevalence rates of hepatitis A)
Anti-HAV Prevalence
Who should receive protection against hepatitis A before travel?
All susceptible persons traveling to or working in countries that have high or intermediate rates of hepatitis A should be vaccinated or receive immune globulin before traveling. Persons from developed countries who travel to developing countries are at high risk for hepatitis A. Such persons include tourists, military personnel, missionaries, and others who work or study abroad in countries that have high or intermediate levels of of hepatitis A. The risk for hepatitis A exists even for travelers to urban areas, those who stay in luxury hotels, and those who report that they have good hygiene and that they are careful about what they drink and eat.
How soon before travel should the first dose of hepatitis A vaccine be given?
For optimal protection, at least 4 weeks prior to travel. Check with your doctor about when the next dose is due.
What should be done if a person cannot receive hepatitis A vaccine?
Travelers who are allergic to a vaccine component or who elect not to receive vaccine should receive a single dose of immune globulin (0.02 mL/kg), which provides effective protection against hepatitis A virus infection for less than 3 months. Travelers whose travel period exceeds 2 months should be administered immune globulin at 0.06 mL/kg; administration must be repeated if the travel period exceeds 5 months.
If travel starts sooner than 4 weeks prior to the first vaccine dose, what should be done?
Because protection might not be optimal until 4 weeks after vaccination, persons traveling to a high-risk area less than 4 weeks after the initial dose of hepatitis A vaccine should also be given immune globulin (0.02 mL/kg), but at a different injection site. Therefore, the first dose of hepatitis A vaccine should be administered as soon as travel to a high-risk area is planned.
What should be done for travelers who are less than 2 years of age to protect them from hepatitis A virus infection?
Immune globulin is recommended for travelers less than 2 years of age because the vaccine is currently not licensed for use in this age group.
Source: MMWR; Prevention of Hepatitis A Through Active or Passive Immunization (PDF)
