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Hep About

Hepatitis A

About Hepatitis A

Hepatitis A is an acute infectious disease of the liver caused by the hepatitis A virus. Many cases have few or no symptoms, especially in the young. The time between infection and symptoms, in those who develop them, is between 2 and 7 weeks. When symptoms occur, they typically last less than 8 weeks and may include nausea, vomiting, diarrhea, jaundice, fever, and abdominal pain. Hepatitis A is primarily spread when an uninfected and unvaccinated person ingests food or water that is contaminated with the feces of an infected person.

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Hepatitis A Is a Serious Disease1-4

  • Approximately 15,000 cases of hepatitis A were reported from 2016-2018—almost a threefold increase from the 3 years prior
  • Around 40% of patients with hepatitis A may require hospitalization
  • People with chronic liver disease, such as those infected with hepatitis C virus, are more likely to become seriously ill and die from hepatitis A

The following groups of people are also at an increased risk of contracting hepatitis A1:

  • International travelers (particularly travel to high-risk countries)
  • Men who have sex with men
  • People who use or inject drugs (all those who use illegal drugs)
  • People with occupational risk for exposure
  • People who anticipate close personal contact with an international adoptee
  • People experiencing homelessness
  • People with HIV
  • Persons with direct contact with someone who has hepatitis A

The CDC can provide more information on hepatitis A.

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If a food handler receives a diagnosis of hepatitis A, immune globulin intramuscular (IGIM) should be administered to other food handlers at the same establishment. Find out more information on the Advisory Committee on Immunization Practices (ACIP) recommendations and guidelines.4  

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Postexposure Prophylaxis for Hepatitis A4

GamaSTAN is indicated for prophylaxis following exposure to hepatitis A. The prophylactic value of GamaSTAN is greatest when given before or soon after exposure to hepatitis A. GamaSTAN is not indicated in persons with clinical manifestations of hepatitis A or in those exposed more than 2 weeks previously.

According to the CDC ACIP, when administered within 2 weeks after exposure to the hepatitis A virus, an IGIM, such as GamaSTAN, is 80% to 90% effective in preventing hepatitis A.  

IGIM should be administered to all previously unvaccinated household and sexual contacts of persons with serologically confirmed hepatitis A. Consideration should also be given to providing IGIM to persons with other types of ongoing close personal contact with a person with hepatitis A (eg, regular babysitting).   

IGIM should be administered to all previously unvaccinated staff and attendees of child care centers or homes if (1) one or more cases of hepatitis A are recognized in children or employees, or (2) cases are recognized in 2 or more households of center attendees.


Learn more about other Hypermunes.



GAMASTAN (immune globulin [human]) is indicated for prophylaxis following exposure to hepatitis A infection, prevention or modification of measles in susceptible persons exposed fewer than 6 days previously, modification of varicella, and modification of rubella in exposed women who will not consider a therapeutic abortion.

Limitations of Use

GAMASTAN is not indicated for routine prophylaxis or treatment of viral hepapitis type B, rubella, poliomyelitis, mumps, or varicella.


Thrombosis may occur with immune globulin products, including GAMASTAN. Risk factors may include: advanced age, prolonged immobilization, hypercoagulable conditions, history of venous or arterial thrombosis, use of estrogens, indwelling central vascular catheters, hyperviscosity, and cardiovascular risk factors. Thrombosis may occur in the absence of known risk factors.

For patients at risk of thrombosis, do not exceed the recommended dose of GAMASTAN. Ensure adequate hydration in patients before administration. Monitor for signs and symptoms of thrombosis and assess blood viscosity in patients at risk for hyperviscosity.

GAMASTAN is contraindicated in patients who have had anaphylactic or severe systemic hypersensitivity reactions to immune globulin (human) and in IgA-deficient patients with antibodies against IgA and a history of hypersensitivity.

Administer GAMASTAN cautiously to patients with a history of prior systemic allergic reactions following the administration of human immunoglobulin preparations. Have epinephrine available for treatment of acute allergic symptoms, should they occur.

Inject intramuscularly only. Do not administer GAMASTAN intravenously because of the potential for serious reactions (eg, renal dysfunction/failure/hemolysis, transfusion-related acute lung injury [TRALI]). Do not inject into a blood vessel.

GAMASTAN is made from human blood; it may carry a risk of transmitting infectious agents, eg, viruses, the variant Creutzfeldt-Jakob disease (vCJD) agent, and, theoretically, the Creutzfeldt-Jakob disease (CJD) agent.

The most common adverse reaction reported for GAMASTAN S/D during post-approval use was fatigue.

Antibodies in GAMASTAN may interfere with the response to live virus vaccines such as measles, mumps, polio, rubella, and varicella. Defer live vaccine administration for up to 6 months after GAMASTAN administration.

Please see full Prescribing Information for GAMASTAN.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088.

hep references


  1. Centers for Disease Control and Prevention. Hepatitis A questions and answers for the public. http://www.cdc.gov/hepatitis/hav/afaq.htm. Reviewed July 28, 2020. Accessed June 7, 2022.
  2. Foster MA, Hofmeister MG, Kupronis BA, et al. Increase in hepatitis A virus infections — United States, 2013-2018. MMWR Morb Mortal Wkly Rep. 2019;68(18):413-415.
  3. Collier MG, Tong X, Xu F. Hepatitis A hospitalizations in the United States, 2002-2011. Hepatology. 2015;61(2):481-485.
  4. Fiore AE, Wasley A, Bell BP; Advisory Committee on Immunization Practices (ACIP). Prevention of hepatitis A through active or passive immunization: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2006;55(RR-07):1-23.