Frequently
Asked Questions About Hepatitis A
GENERAL
INFORMATION
- Signs
and symptoms
- Transmission
- Prevention
HEPATITIS
A VACCINE AND IMMUNE GLOBULIN
- Vaccine Schedules
- Vaccine Safety
- Immune globulin supply
WHO
SHOULD GET VACCINATED AGAINST HEPATITIS A?
WHO
DOES NOT ROUTINELY NEED HEPATITIS A VACCINE?
INTERNATIONAL
TRAVEL
- Who should get vaccinated
- Vaccine schedule before travel
- World map showing hepatitis A prevalence
| GENERAL
INFORMATION |
![[up]](/peth04/20041030072700im_/http://www.cdc.gov/ncidod/diseases/hepatitis/images/uparrow.gif)
What is hepatitis A?
Hepatitis A is a liver disease caused by hepatitis A virus.
How is hepatitis A virus transmitted?
Hepatitis A virus is spread from person to person by putting something
in the mouth that has been contaminated with the stool of a person with
hepatitis A. This type of transmission is called "fecal-oral."
For this reason, the virus is more easily spread in areas where there
are poor sanitary conditions or where good personal hygiene is not observed.
Most infections result from contact with a household member or sex partner
who has hepatitis A. Casual contact, as in the usual office, factory,
or school setting, does not spread the virus.
What are the signs and symptoms of hepatitis
A?
Persons with hepatitis A virus infection may not have any signs or symptoms
of the disease. Older persons are more likely to have symptoms than
children. If symptoms are present, they usually occur abruptly
and may include fever, tiredness, loss of appetite, nausea, abdominal
discomfort, dark urine, and jaundice (yellowing of the skin and eyes).
Symptoms usually last less than 2 months; a few persons are ill for
as long as 6 months. The average incubation period for hepatitis A is
28 days (range: 15–50 days).
How do you know if you have hepatitis A?
A blood test (IgM anti-HAV) is needed to diagnose hepatitis A. Talk
to your doctor or someone from your local health department if you suspect
that you have been exposed to hepatitis A or any type of viral hepatitis.
How can you prevent hepatitis A?
Always wash your hands after using the bathroom, changing a diaper,
or before preparing or eating food.
Two products are used to prevent hepatitis A virus infection:
immune globulin and hepatitis A vaccine.
- 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.
- Hepatitis A vaccine
has been licensed in the United States for use in persons 2 years
of age and older. The vaccine is recommended (before exposure to hepatitis
A virus) for persons who are more likely to get hepatitis A virus
infection or are more likely to get seriously ill if they do get hepatitis
A. The vaccines currently licensed in the United States are
HAVRIX® (manufactured by GlaxoSmithKline) and VAQTA®
(manufactured by Merck & Co., Inc).
| HEPATITIS
A VACCINE AND IMMUNE GLOBULIN |
Hepatitis A Vaccine
What are the dosages and schedules for hepatitis
A vaccines?
Recommended
dosages of HAVRIX®¹
|
Vaccinee's
age
(years) |
Dose
(EL.U.)² |
Volume
(mL) |
No.
doses |
Schedule
(mos)³ |
|
| 2-18 |
720 |
0.5 |
2 |
0,6-12 |
| >18 |
1,440 |
1.0 |
2 |
0,6-12 |
|
| ¹ |
Hepatitis
A vaccine, inactivated, GlaxoSmithKline. |
| ² |
ELISA
units. |
| ³ |
0
months represents timing of the initial dose; subsequent
numbers represent months after the initial dose. |
|
Recommended dosages
of VAQTA®¹
|
Vaccinee's
age
(years) |
Dose(U)² |
Volume
(mL) |
No.
doses |
Schedule
(mos)³ |
|
| 2-18 |
25 |
0.5 |
2 |
0,6-18 |
| >18 |
50 |
1.0 |
2 |
0,6-12 |
|
| ¹ |
Hepatitis
A vaccine, inactivated, Merck & Co., Inc. |
| ² |
Units. |
| ³ |
0
months represents timing of the initial dose; subsequent
numbers represent months after the initial dose. |
|
Can
a patient receive the first dose of hepatitis A vaccine from one manufacturer
and the second (last) dose from another manufacturer?
Yes. Although studies have not been done to look at this issue,
there is no reason to believe that this would be a problem.
What should be done if the second (last)
dose of hepatitis A vaccine is delayed?
The second dose should be administered as soon as possible.
There is no need to repeat the first dose.
Can other vaccines be given at the same
time that hepatitis A vaccine is given?
Yes. Hepatitis B, diphtheria, poliovirus (oral and inactivated),
tetanus, oral typhoid, cholera, Japanese encephalitis, rabies,
yellow fever vaccine or immune globulin can be given at the same time
that hepatitis A vaccine is given, but at a different injection site.
Is hepatitis A vaccine safe?
Yes, hepatitis A vaccine has an excellent safety profile. No serious
adverse events have been attributed definitively to hepatitis A vaccine.
Soreness at the injection site is the most frequently reported side
effect.
Any adverse event suspected to be associated with hepatitis A vaccination
should be reported to the Vaccine
Adverse Events Reporting System (VAERS). VAERS forms can be obtained
by calling 1-800-822-7967.
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 pre-vaccination testing be done?
Pre-vaccination 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 post-vaccination 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 (external
link)
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 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/1000,000) 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 non-injecting
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 up to 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
The use of commercial
sources and trade names is for identification and does not imply endorsement
by the Public Health Service or the U.S. Department of Health and
Human Services.
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