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Hepatitis A
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What is Hepatitis A
Hepatitis A Vaccine

What is Hepatitis A

Hepatitis is an inflammation of the liver. Hepatitis A is a vaccine-preventable, communicable disease of the liver caused by the hepatitis A virus (HAV) 1. Hepatitis A is usually transmitted person-to-person through the fecal-oral route or consumption of contaminated food or water. Hepatitis A is uncommon in the US, but certain groups are at increased risk. This includes travelers to parts of the world with poor levels of sanitation, men who have sex with men, and people who inject drugs.

Hepatitis A is a self-limited disease that does not result in chronic infection and most people make a full recovery within a couple of months. Most adults with hepatitis A have symptoms, including fatigue, low appetite, stomach pain, nausea, and jaundice, that usually resolve within 2 months of infection; most children less than 6 years of age do not have symptoms or have an unrecognized infection. Antibodies produced in response to hepatitis A infection last for life and protect against reinfection. But hepatitis A can occasionally last for many months and, in rare cases, it can be life threatening if it causes the liver to stop working properly (liver failure) and the need for an emergency liver transplant to survive. The best way to prevent hepatitis A infection is to get vaccinated.

Hepatitis A, is caused by the hepatitis A virus (HAV). The disease spreads through contact with an infected person’s stool. You can get it from:

  • Eating food made by an infected person who did not wash their hands after using the bathroom
  • Drinking untreated water or eating food washed in untreated water
  • Putting into your mouth a finger or object that came into contact with an infected person’s stool
  • Having close contact with an infected person, such as through sex or caring for someone who is ill.

In rare cases, hepatitis A can cause a sudden loss of liver function, especially in older adults or people with chronic liver diseases. Acute liver failure requires a stay in the hospital for monitoring and treatment. Some people with acute liver failure may need a liver transplant.

Hepatitis A is more common in developing countries where sanitation is poor and access to clean water is limited. Hepatitis A is more common in parts of Africa, Asia, Central and South America, and Eastern Europe than it is in the United States.

How common is hepatitis A virus infection in the United States?

Hepatitis A rates in the United States have declined by more than 95% since hepatitis A vaccine first became available in 1995. Incidence decreased more than 95% from 1995 to 2011 (Figure 1). In 2015, a total of 1,390 cases of hepatitis A were reported to Centers for Disease Prevention and Control (CDC) from 50 states, a 12.2% increase from the number of reported cases in 2014. However, the overall incidence rate in 2015 was 0.4 cases per 100,000 population, the same as 2014. After adjusting for under-ascertainment and under-reporting, an estimated 2,800 hepatitis A cases occurred in 2015. However, reported hepatitis A cases have increased dramatically since 2016, when large person-to-person outbreaks began occurring (Figure 2). Hepatitis A incidence increased 1,325% from 2015 through 2019. In 2019, a total of 18,846 cases of hepatitis A were reported in the United States, but due to underreporting, the actual number of cases is likely around 37,700 2. The increase in 2019 was because of unprecedented person-to-person outbreaks reported in 31 states primarily among people who use drugs and people experiencing homelessness.

Figure 1. Hepatitis A incidence rate 1984-2015

hepatitis a - incidence 2015

Figure 2. Hepatitis A incidence rate 2011-2018

[Source 3 ]

What is the incubation period for hepatitis A virus?

The average incubation period for hepatitis A virus is 28 days (range: 15–50 days) 4.

How long does hepatitis A virus survive outside the body?

Hepatitis A virus can live outside the body for months, depending on the environmental conditions.

How is the hepatitis A virus killed?

In contaminated food, hepatitis A virus is killed when exposed to temperatures of >185 degrees F (>85 degrees C) for 1 minute. However, the virus can still be spread from cooked food that is contaminated after cooking. Freezing does not inactivate hepatitis A virus.

Adequate chlorination of water, as recommended in the United States, kills hepatitis A virus that enters the municipal water supply 5. Transmission of hepatitis A virus from exposure to contaminated water is considered rare given that no substantial or consistent increase in prevalence of anti-hepatitis A virus has been documented among sewage workers.

In the environment, hepatitis A virus can be killed by cleaning household or other facility surfaces with a freshly prepared solution of 1:100 dilution of household bleach to water 6.

Can hepatitis A become chronic?

No. Unlike other types of viral hepatitis, hepatitis A does not cause long-term liver damage, and it doesn’t become chronic.

Can persons become re-infected with hepatitis A virus?

No. IgG antibodies to hepatitis A virus (HAV), which appear early in the course of infection, provide lifelong protection against the disease 7.

How is Hepatitis A Transmitted

Hepatitis A is caused by hepatitis A virus that infects liver cells and causes inflammation. The inflammation can affect how your liver works and cause other signs and symptoms of hepatitis A.

Hepatitis A virus most commonly spreads when you eat or drink something contaminated with fecal matter, even just tiny amounts. Hepatitis A virus does not spread through sneezing or coughing. Hepatitis A is most widespread in parts of the world where standards of sanitation and food hygiene are generally poor, such as parts of Africa, the Indian subcontinent, the Far East, the Middle East, and Central and South America.

You can get hepatitis A infection from:

  • Person-to-person transmission through the fecal-oral route (i.e., ingestion of something that has been contaminated with the feces of an infected person) is the primary means of hepatitis A virus transmission in the United States. Infections in the United States result primarily from travel to another country where hepatitis A virus transmission is common (eating food prepared by someone with the infection who has not washed their hands properly or washed them in water contaminated with sewage), close personal contact with infected persons, sex among men who have sex with men, having sex with someone who has the virus and behaviors associated with injection drug use 8, 9 [see 10].
  • Exposure to contaminated food or water, including ice cubes, can cause common-source outbreaks and sporadic cases of Hepatitis A virus infection. Uncooked foods contaminated with Hepatitis A virus (e.g., eating raw or undercooked shellfish from contaminated water) can be a source of outbreaks, as well as cooked foods that are not heated to temperatures capable of killing the virus during preparation (i.e., 185 °F [>85 °C] for one minute) and foods that are contaminated after cooking, as occurs in outbreaks associated with infected food handlers 11. Waterborne outbreaks are infrequent in developed countries with properly maintained sanitation and water supplies 12. In the United States, floods are unlikely to cause outbreaks of communicable diseases, and outbreaks of Hepatitis A virus caused by flooding have not been documented [see 13].

Someone with hepatitis A is most infectious from around 2 weeks before symptoms appear until about a week after symptoms first develop.

Hepatitis A is found worldwide, but areas where it’s most widespread include:

  • sub-Saharan and northern Africa
  • the Indian subcontinent (particularly India, Bangladesh, Pakistan and Nepal)
  • some parts of the Far East (excluding Japan)
  • the Middle East
  • South and Central America

Who is at increased risk for acquiring hepatitis A virus infection?

Although anyone can get hepatitis A, in the United States, certain groups of people are at higher risk for getting infected and for having severe disease if they do get hepatitis A.

People at increased risk for hepatitis A virus infection:

  • International travelers to countries with high or intermediate endemicity of hepatitis A virus infection
  • Men who have sex with men
  • People who use injection or noninjection drugs (all those who use illegal drugs)
  • People with occupational risk for exposure
  • Persons with direct contact with persons who have hepatitis A
  • Have any type of sexual contact with someone who has hepatitis A
  • Persons with clotting factor disorders, such as hemophilia
  • Persons working with nonhuman primates
  • Live with or care for someone who has hepatitis A
  • People experiencing unstable housing or homelessness
  • Live with or care for a child recently adopted from a country where hepatitis A is common

People at increased risk for severe disease from hepatitis A virus infection:

  • People with chronic liver disease
  • People with human immunodeficiency virus (HIV) infection

How can I protect myself from hepatitis A infection?

You can protect yourself from hepatitis A by getting the hepatitis A vaccine. If you have not had the hepatitis A vaccine, you can take steps to reduce your chance of infection.

If you have had hepatitis A in the past, you cannot get hepatitis A again. You can still get other types of viral hepatitis though.

If you’re traveling to parts of the world where hepatitis A outbreaks occur, take these steps to prevent hepatitis A infection:

  • Peel and wash all fresh fruits and vegetables yourself.
  • Don’t eat raw or undercooked meat and fish.
  • Drink bottled water and use it when brushing your teeth.
  • Avoid all beverages of unknown purity, with or without ice.
  • If bottled water isn’t available, boil tap water before drinking it.
  • Thoroughly wash your hands often, especially after using the toilet or changing a diaper and before preparing food or eating.

What causes hepatitis A?

Hepatitis A virus causes hepatitis A and spreads through contact with an infected person’s stool. Hepatitis A virus is a member of the Hepatovirus genus of the family Picornaviridae, and is a nonenveloped single-stranded RNA virus 14. Hepatitis A virus replicates in hepatocytes (liver cells) and interferes with liver function, sparking an immune response that causes liver inflammation. Four of the seven genotypes of hepatitis A virus affect humans (genotypes 1 and 3 are the most common), but only one serotype exists. Infection with any of the hepatitis A virus genotypes usually results in lifelong immunity against all strains of hepatitis A virus 15.

The World Health Organization (WHO) estimates that approximately 1.5 million people are infected with hepatitis A virus each year 15. Endemic rates are high in developing countries with low socioeconomic conditions and poor sanitation and hygiene practices. Exposure in these developing countries usually occurs in childhood. Infection rates are low in developed countries such as the United States, Canada, and Western Europe. High-risk groups in low endemicity countries have been identified as injection-drug users, men who have sex with men, people traveling to endemic areas, and isolated communities such as nursing homes and even day-care centers 16. The incidence of hepatitis A virus in a given population correlates with socioeconomic properties such as income, the density of housing, sanitation, and water quality.

Most cases of hepatitis A transmission are from person to person and limited to close contacts. The virus most commonly spreads when you eat or drink something contaminated with fecal matter, even just tiny amounts. Blood transfusion is a very rare cause of hepatitis A. It does not spread through sneezing or coughing.

Here are some of the specific ways the hepatitis A virus can spread:

  • Eating food handled by someone with the virus who doesn’t thoroughly wash his or her hands after using the toilet
  • Drinking contaminated water or eating food washed in untreated water
  • Eating raw shellfish from water polluted with sewage
  • Being in close contact with a person who’s infected — even if that person has no signs or symptoms
  • Having sex with someone who has the virus
  • Placing a finger or an object in your mouth that came into contact with an infected person’s stool

You CANNOT get hepatitis A from:

  • being coughed on or sneezed on by an infected person
  • sitting next to an infected person
  • hugging an infected person
  • A baby cannot get hepatitis A from breast milk 17

Risk factors for hepatitis A

You’re at increased risk of hepatitis A if you:

  • Travel or work in areas of the world where hepatitis A is common
  • Are HIV positive
  • Are a man who has sexual contact with other men
  • Have any type of sexual contact with someone who has hepatitis A
  • Live with another person who has hepatitis A
  • Are experiencing homelessness
  • Have a clotting-factor disorder, such as hemophilia
  • Use any type of illegal drugs (not just those that are injected)
  • Institutionalized
  • Attend child care or work in a child care center

Hepatitis A Virus Genotypes

There are 6 hepatitis A virus genotypes, with only genotypes 1, 2 and 3 infecting humans. Hepatitis A virus genotypes 1, 2 and 3 are further divided into subtypes A and B. Hepatitis A virus genotypes and subtypes have a distinctive geographic distribution 18.

  • Hepatitis A virus genotype 1 is the most common genotype occurring around the world
  • Hepatitis A virus genotype 1A is prevalent in South and North America, Europe, Asia and Africa
  • Hepatitis A virus genotype 1B is predominant in the Middle East and South Africa
  • Hepatitis A virus genotype 2 is not as common
  • Hepatitis A virus genotype 3 is common around the world
  • Hepatitis A virus genotype 3A circulates in Asia, Europe, Madagascar and the USA.

What are the clinical implications of different hepatitis A virus genotypes?

No differences in clinical presentation of infections with different Hepatitis A virus genotypes are clearly established. However, hepatitis A virus genotype 1B is found more frequently among acute liver failure cases compared to the non-liver failure cases, suggesting its potential greater virulence. Host factors such as age of patients and underlying liver diseases as well as viral factors such as Hepatitis A virus RNA levels and genomic mutations were reported in some studies to be associated with disease severity 19.

How does hepatitis A genotyping help to establish transmission in an outbreak setting ?

Hepatitis A genotyping is done to determine genetic identity of the HAV sequences in an outbreak. Sequence differences in the VP1-P2A junction of the hepatitis A virus genome has been widely used to identify Hepatitis A virus sub-genotypes, and evaluate genetic relatedness among sequences derived from hepatitis A infected individuals 20. Genotyping assists significantly in the identification of a common source of infection during hepatitis A outbreaks, especially when paired with epidemiologic evidence 21.

Signs and symptoms of hepatitis A virus infection

Among older children and adults, infection is typically symptomatic. Symptoms usually occur abruptly and can include the following:

  • Fever (low grade fever)
  • Fatigue
  • Loss of appetite
  • Sudden Nausea
  • Sudden Vomiting
  • Abdominal pain or discomfort, especially on the upper right side beneath your lower ribs (by your liver)
  • Dark urine
  • Clay-colored bowel movements
  • Joint pain
  • Jaundice or yellowing of the skin and the whites of your eyes
  • Intense itching

Most (70%) of infections in children younger than age 6 are not accompanied by symptoms. When symptoms are present, young children typically do not have jaundice; most (>70%) older children and adults with hepatitis A virus infection have this symptom 22. These symptoms may be relatively mild and go away in a few weeks. Sometimes, however, hepatitis A infection results in a severe illness that lasts several months.

When to see your doctor

Make an appointment with your doctor if you have signs or symptoms of hepatitis A.

Getting a hepatitis A vaccine or an injection of immunoglobulin (an antibody) within two weeks of exposure to hepatitis A may protect you from infection. Ask your doctor or your local health department about receiving the hepatitis A vaccine if:

  • You’ve traveled out of the country recently, particularly to Mexico or South or Central America, or to areas with poor sanitation
  • A restaurant where you recently ate reports a hepatitis A outbreak
  • Someone close to you, such as a roommate or caregiver, is diagnosed with hepatitis A
  • You recently had sexual contact with someone who has hepatitis A

When symptoms occur, how long do they last?

Symptoms of hepatitis A usually last less than 2 months, although 10%–15% of symptomatic persons have prolonged or relapsing disease for up to 6 months 23.

Hepatitis A complications

Unlike other types of viral hepatitis, hepatitis A does not cause long-term liver damage, and it doesn’t become chronic. People typically recover from hepatitis A without complications. In rare cases, hepatitis A may lead to liver failure. Liver failure due to hepatitis A is more common in adults older than age 50 and in people who have another liver disease 3. Acute liver failure requires a stay in the hospital for monitoring and treatment. Some people with acute liver failure may need a liver transplant.

How is hepatitis A infection prevented?

According to the World Health Organization (WHO), the most effective way to prevent hepatitis A virus infection is to improve sanitation, food safety, and immunization practices. In the United States, vaccination with the full, two-dose series of hepatitis A vaccine is the best way to prevent hepatitis A infection. Hepatitis A vaccine is typically given in two shots. The first one is followed by a booster shot six months later. Hepatitis A vaccine has been licensed in the United States for use in persons 1 year of age and older. Vaccination against hepatitis A is available as inactivated, single-antigen vaccines (hepatitis A virusRIX and VAQTA) or in combination with hepatitis B (TWINRIX). Additional Guidance is available at: https://www.cdc.gov/mmwr/preview/mmwrhtml/rr5507a1.htm

The Centers for Disease Control and Prevention (CDC) recommends a hepatitis A vaccine for the following people:

  • All children at age 1, or older children who didn’t receive the childhood vaccine
  • Anyone age 1 year or older who is experiencing homelessness
  • Infants ages 6 to 11 months traveling internationally
  • Family and caregivers of adoptees from countries where hepatitis A is common
  • People in direct contact with others who have hepatitis A
  • Laboratory workers who may come in contact with hepatitis A
  • Men who have sex with men
  • People who work or travel in parts of the world where hepatitis A is common
  • People who use any type of illicit drugs, not just injected ones
  • People with clotting-factor disorders
  • People with chronic liver disease, including hepatitis B or hepatitis C
  • Anyone wishing to obtain protection (immunity)

If you’re concerned about your risk of hepatitis A, ask your doctor if you should be vaccinated.

Follow safety precautions when traveling

  • If you’re traveling to parts of the world where hepatitis A outbreaks occur, take these steps to prevent infection:
    • Peel and wash all fresh fruits and vegetables yourself.
    • Don’t eat raw or undercooked meat and fish.
    • Drink bottled water and use it when brushing your teeth.
    • Avoid all beverages of unknown purity, with or without ice.
    • If bottled water isn’t available, boil tap water before drinking it.

Practice good hygiene

  • Thoroughly wash your hands often, especially after using the toilet or changing a diaper and before preparing food or eating.

Given that hepatitis A virus is transmitted through the fecal-oral route, good hand hygiene—including hand washing after using the bathroom, changing diapers, and before preparing or eating food—is integral to hepatitis A prevention 24.

Prevent infection after contact with the virus

If you think you have come in contact with the hepatitis A virus, see your doctor right away. A dose of the hepatitis A vaccine or a medicine called hepatitis A immune globulin may protect you from getting the infection. Your doctor may recommend a vaccine dose or hepatitis A immune globulin if:

  • you live with, have had sex with, or have had close contact with someone who has hepatitis A
  • you shared illegal drugs with someone who had hepatitis A
  • you ate food or drank water possibly containing the hepatitis A virus

You must get the vaccine dose or medicine shortly after coming into contact with the virus to prevent infection.

Hepatitis A Immune Globulin

Immune globulin can provide short-term protection against hepatitis A, both pre- and post-exposure. Immune globulin must be administered within 2 weeks after exposure for maximum protection. Additional Guidance is available at: 25

GamaSTAN™ S/D is the only immune globulin (IG) product approved by the U.S. Food and Drug Administration (FDA) for hepatitis A virus prophylaxis 26. GamaSTAN™ S/D (Grifols Therapeutics, Inc., Research Triangle Park, North Carolina) is a sterile, preservative-free solution of immune globulin (IG) for intramuscular administration and is used for prophylaxis against disease caused by infection with hepatitis A, measles, varicella, and rubella viruses.

Following are the updated recommended doses of GamaSTAN S/D immune globulin for hepatitis A pre-exposure and post-exposure prophylaxis 27.

Pre-exposure Prophylaxis in Persons Who Plan to Travel in Areas with High or Intermediate Hepatitis A Endemicity

The recommended dosages of GamaSTAN S/D immune globulin, which vary according to planned duration of travel are as follows (see Table 1):

  • Up to 1 month: 0.1 mL/kg
  • Up to 2 months: 0.2 mL/kg
  • 2 months or longer: repeat dose of 0.2 mL/kg every 2 months.

Table 1. Indications and updated dosage recommendations for GamaSTAN S/D human immune globulin for preexposure and postexposure prophylaxis against hepatitis A infection

IndicationUpdated dosage recommendation
Preexposure prophylaxis
Up to 1 month of travel0.1 mL/kg
Up to 2 months of travel0.2 mL/kg
2 months of travel or longer0.2 mL/kg (repeat every 2 months)
Postexposure prophylaxis0.1 mL/kg
[Source 25 ]

Pre-exposure Prophylaxis for International Travel

Hepatitis A vaccine at the age-appropriate dose is preferred to immune globulin. For travel that will begin in ≤2 weeks to countries with high or intermediate hepatitis A endemicity, older adults, immunocompromised persons, and persons with chronic liver disease or other chronic medical conditions may receive immune globulin simultaneously with hepatitis A vaccine at a separate anatomic injection site. Travelers who elect not to receive hepatitis A vaccine, who are aged <12 months, or who are allergic to a component of hepatitis A vaccine should receive a single dose of immune globulin before travel 28.

Post-exposure Prophylaxis

Immune globulin (Dose 0.1 mL/kg) should be used for children aged <12 months, immunocompromised persons, persons who have chronic liver disease, and persons for whom vaccine is contraindicated. Immune globulin is also preferred over hepatitis A vaccine for persons aged >40 years; however, vaccine may be used if immune globulin cannot be obtained 28.

What are the current CDC guidelines for postexposure protection against hepatitis A?

Hepatitis A vaccine should be administered as soon as possible, within 2 weeks of exposure, to all unvaccinated people aged ≥12 months who have recently been exposed to hepatitis A virus (HAV). In addition to hepatitis A vaccine, co-administration of GamaSTAN S/D immune globulin (0.1 mL/kg) is recommended under certain circumstances according to age and health status of the exposed person.

What should be done when a case of hepatitis A is found in a setting providing services to children or adults (e.g., a school, hospital, office setting, corrections facility, or homeless shelter)?

  • Postexposure prophylaxis is not routinely indicated when a single case occurs in an elementary or secondary school or an office or other work setting and the source of infection is outside of the setting.
  • When a person who has hepatitis A virus infection is admitted to a hospital, staff members should not routinely be administered postexposure prophylaxis; instead, appropriate infection control practices should be emphasized (see standard and contact precautions for diapered or incontinent patients).
  • Postexposure prophylaxis should be administered to people who have close contact with index patients if an epidemiologic investigation indicates hepatitis A virus transmission has occurred among students in a school or among patients or between patients and staff members in a hospital.
  • Postexposure prophylaxis should be considered for all previously unvaccinated residents and employees when a confirmed hepatitis A case occurs in a setting where close personal contact occurs regularly and hygiene standards are difficult to maintain (e.g., correctional facility, homeless shelter, psychiatric facility, group home or residential facility for the disabled). In a setting containing multiple enclosed units or sections (e.g., prison ward), PEP administration should be limited only to people in the area where there is exposure risk.

Postexposure Prophylaxis of Household and Institutional Hepatitis A Case Contacts

The recommended dosage of GamaSTAN S/D immune globulin is 0.1 mL/kg (see Table 1 above). There is no maximum dosage of GamaSTAN S/D immune globulin for hepatitis A prophylaxis 8.

The effect of immune globulin preparations on the response to certain live-virus vaccines is unknown, but antibodies in GamaSTAN S/D immune globulin might interfere with live-virus vaccines such as measles, mumps, and rubella (MMR) vaccine and varicella vaccine 11. The recommendations for the timing of administration of GamaSTAN S/D immune globulin with live-virus vaccines has not changed 11. The Advisory Committee on Immunization Practices (ACIP) recommends that MMR and varicella vaccines should be administered at least 2 weeks before or at least 3 months after the administration of immune globulin preparations 8. If an immune globulin preparation must be administered less than 2 weeks after the administration of MMR or varicella vaccine, the patient should be revaccinated no sooner than 3 months after receipt of the immune globulin preparation.

The absolute lower limit of anti-hepatitis A immune globulin required to prevent hepatitis A virus infection has not been defined; however, 10 mIU/mL is considered to be the minimum protective level for hepatitis A prophylaxis 29. The minimum anti-hepatitis A immune globulin potency specified by the European Pharmacopoeia for intramuscular immune globulin preparations indicated for hepatitis A prophylaxis is >100 IU/mL 30. A recent study showed that only two of nine tested lots of commercially available immune globulin preparations manufactured in the United States, Europe, and Asia had anti-hepatitis A immune globulin potency of 100 IU/mL 12. In addition, anti-hepatitis A immune globulin decay models indicate that only five of nine lots of immune globulin dosed at 0.02 mL/kg achieved postabsorption plasma anti-hepatitis A immune globulin levels above the minimum protective level of 10 mIU/mL 12. The decay model also showed that none of the tested immune globulin lots maintained the proposed minimal protective anti-hepatitis A immune globulin level of 10 mIU/mL for 3 months 12.

Indications for the use of immune globulin are based on Advisory Committee on Immunization Practices (ACIP) recommendations published in 2007 for prevention of hepatitis A infection after exposure to hepatitis A virus and in international travelers 28.

Do immunocompromised people require additional protection after being exposed to someone with hepatitis A?

Yes. People who are immunocompromised or have chronic liver disease and who have been exposed to hepatitis A virus within the past 2 weeks and have not previously completed the 2-dose hepatitis A vaccination series should receive both immune globulin (0.1 mL/kg) and hepatitis A vaccine simultaneously in a different anatomic site (e.g., separate limbs) as soon as possible after exposure. When the dose of hepatitis A vaccine administered is the first dose the exposed individual has received, a second dose should be administered 6 months after the first for long-term protection.

Should pregnant women at increased risk for exposure to the hepatitis A virus receive postexposure prophylaxis?

Women with increased likelihood of exposure to hepatitis A virus during pregnancy can be administered immune globulin (0.1 mL/kg). There has been no observed increase in maternal or infant adverse events after hepatitis A vaccination or immune globulin administration in pregnancy.

Hepatitis A Vaccine

Who should be vaccinated against hepatitis A?

The Advisory Committee on Immunization Practices (ACIP) recommends that the following persons be vaccinated against hepatitis A:

  • All children aged 12–23 months
  • Unvaccinated children and adolescents aged 2–18 years
  • Persons who are at increased risk for infection
    • International travelers
    • Men who have sex with men
    • People who use injection or noninjection 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
    • Unvaccinated people in outbreak settings who are at risk for hepatitis A virus infection or at risk for severe disease from hepatitis A virus
    • Pregnant women at risk for hepatitis A virus infection or severe outcome from hepatitis A virus infection
  • Persons who are at increased risk for complications from hepatitis A
    • People with chronic liver disease
    • People with human immunodeficiency virus infection
  • Any person wishing to obtain immunity (protection)

Hepatitis A vaccination is NO longer recommended by ACIP

  • People who receive blood products for clotting disorders (e.g., hemophilia)

Children

Advisory Committee on Immunization Practices (ACIP) recommends that all children in the United States receive hepatitis A vaccine at 1 year of age (i.e., 12-23 months) to avoid interference by passive maternal anti-hepatitis A (hepatitis A antibody) that may be present during the first year of life. In the United States, children who are not vaccinated by 2 years of age can be vaccinated at subsequent visits; vaccination can be considered for children 2 to 18 years old and for anyone who wants protection against hepatitis A infection. Booster doses are not recommended. More information is available at: 31

What if an infant receives the first dose of hepatitis A vaccine at an age younger than 12 months?

Although no known harm is associated with giving hepatitis A vaccine to infants, the hepatitis A vaccine dose(s) administered prior to 12 months of age might result in a suboptimal immune response, particularly in infants with passively acquired maternal antibody 32. Therefore, hepatitis A vaccine dose(s) administered at <12 months of age are not considered valid doses.

The two-dose hepatitis A vaccine series should be initiated when the child is at least 1 year of age.

Persons at Increased Risk for Hepatitis A Infection

Persons traveling to or working in countries that have high or intermediate endemicity of hepatitis A. Persons who travel to developing countries are at high risk for hepatitis A, even those traveling to urban areas, staying in luxury hotels, and those who report maintaining good hand hygiene and being careful about what they drink and eat [see 33].

Men who have sex with men. Men who have sex with men should be vaccinated.

Users of injection and non-injection drugs. Persons who use injection and non-injection drugs should be vaccinated.

Persons who have occupational risk for infection. Persons who work with HAV-infected primates or with HAV in a research laboratory setting should be vaccinated. No other groups have been shown to be at increased risk for HAV infection because of occupational exposure.

Persons who have chronic liver disease. Persons with chronic liver disease who have never had hepatitis A should be vaccinated, as they have a higher likelihood of having fulminant hepatitis A (i.e., rapid onset of liver failure, often leading to death). 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 vaccinated.

Household members and other close personal contacts of adopted children newly arriving from countries with high or intermediate hepatitis A endemicity. Previously unvaccinated persons who anticipate close personal contact (e.g., household contact or regular babysitting) with an international adoptee from a country of high or intermediate endemicity during the first 60 days following arrival of the adoptee in the United States should be vaccinated. The first dose of the 2-dose hepatitis A vaccine series should be administered as soon as adoption is planned, ideally 2 or more weeks before the arrival of the adoptee. More information is available at: 34.

Persons with direct contact with persons who have hepatitis A. Persons who have been recently exposed to hepatitis A virus and who have not previously received hepatitis A vaccine should be vaccinated. See 35

What is the Hepatitis A vaccine schedule and dosages ?

HAVRIX ® 1

Licensed dosages and schedules for HAVRIX ® 1
AgeDose (ELISA units)2Volume (mL)No. of dosesSchedule (mos)3
7200.520,6-12
1,4401.020,6-12

1Hepatitis A vaccine, inactivated, GlaxoSmithKline.
2Enzyme-linked immunosorbent assay units.
30 months represents timing of the initial dose; subsequent numbers represent months after the initial dose.

VAQTA ® 1

Licensed dosages and schedules for VAQTA ® 1
AgeDose (U.)2Volume (mL)No. of dosesSchedule (mos)3
12 mos–18 yrs250.520,6-18
≥19 years501.020,6-18

1Hepatitis A vaccine, inactivated, Merck & Co., Inc.
2Units.
30 months represents timing of the initial dose; subsequent numbers represent months after the initial dose.

TWINRIX ® 1 (HepAHepB) Vaccine Schedule (Not recommended for post exposure prophylaxis)

Licensed dosages and schedules for TWINRIX ® 1
AgeDose (ELISA units)2Volume (mL)No. of dosesSchedule
≥ 18 yrs7201.030, 1, 6 mos
≥ 18 yrs7201.040, 7, 21–30 days + 12 mos3

1Combined hepatitis A and hepatitis B vaccine, inactivated, GlaxoSmithKline.
2Enzyme-linked immunosorbent assay units.
3This 4-dose schedule enables patients to receive 3 doses in 21 days; this schedule is used prior to planned exposure with short notice and requires a fourth dose at 12 months.

Can hepatitis A vaccine be given during pregnancy?

Yes 3. Hepatitis A vaccine is recommended for pregnant women with additional medical conditions or other indications for hepatitis A vaccine. The Adult Immunization Schedule by Medical and Other Indications is available at: 36

A recent review of the Vaccine Adverse Event Reporting System (VAERS) did not identify any concerning patterns of adverse events in pregnant women or their infants after hepatitis A vaccination (HAVRIX, VAQTA) or hepatitis A and B combined vaccination (TWINRIX) during pregnancy 37. Pregnant women at risk for HAV infection during pregnancy should also be counseled concerning all options to prevent HAV infection.

Can Hepatitis A vaccine be given to immunocompromised persons (e.g., persons on hemodialysis or persons with AIDS)?

Yes. Because hepatitis A vaccine is inactivated, no special precautions need to be taken when vaccinating immunocompromised persons.

Is it harmful to administer an extra dose(s) of hepatitis A vaccine or to repeat the entire vaccine series if documentation of vaccination history is unavailable?

No. If necessary, administering extra doses of hepatitis A vaccine is not harmful.

Is it worthwhile to administer the first dose of hepatitis A vaccine if the timing of the second dose cannot be assured?

Yes, It is not known for how long protection from one hepatitis A vaccine dose lasts, but it has been shown to last for at least 10 years 38. One dose of single-antigen hepatitis A vaccine administered at any time before International travel can provide adequate protection for most healthy persons 35.

How soon before international travel should the first dose of hepatitis A vaccine be given?

All unvaccinated people ≥12 months of age (including those with immunocompromising conditions and people with chronic liver disease) planning travel to an area with high or intermediate hepatitis A virus endemicity should receive a single dose of vaccine as soon as travel is considered; they should then complete the vaccine series with the appropriate dose and schedule. People traveling within 2 weeks (i.e., <2 weeks) should receive the initial dose of hepatitis A vaccine before departure and also simultaneously may be administered immune globulin at a separate anatomic injection site (e.g., separate limbs) for additional short-term protection 39. The hepatitis A vaccine series should be completed according to the routine schedule.

What should be done to protect international travelers <6 months of age and other travelers unable to receive hepatitis A vaccine?

Infants aged <6 months and travelers for whom vaccine is contraindicated or who elect not to receive vaccine should receive immune globulin before travel when protection against hepatitis A virus is recommended. Information on immune globulin dosing is available.

What should be done to protect international travelers 6–11 months of age?

Hepatitis A vaccine should be administered to infants aged 6–11 months traveling outside the United States when protection against hepatitis A is recommended. This vaccine dose does not count towards the 2-dose series. The 2-dose hepatitis A vaccine series should then be initiated at age 12 months (at any interval after the dose administered for international travel preexposure prophylaxis) according to the routine, age-appropriate vaccine schedule.

Do health-care personnel need routine vaccination against hepatitis A?

No. Hepatitis A vaccine is not routinely recommended for health-care personnel, because health-care-associated transmission of hepatitis A virus is rare in the United States.

Which groups are at low risk and do NOT need routine vaccination against hepatitis A?

  • People with clotting-factor disorders. Although this group was once recommended to receive routine vaccination, the risk for hepatitis A virus (hepatitis A virus) transmission via transfusion of blood products among people with clotting factor disorders is now considered the same as that among the general population 40. Source plasma is now screened for hepatitis A virus 41.
  • Food handlers. Hepatitis A vaccination is not specifically recommended for people who handle food in the absence of other risk factors. Foodborne hepatitis A outbreaks occur relatively infrequently in the United States. It is rare for food handlers with hepatitis A virus infection to transmit hepatitis A virus through their workplace to customers. Food handlers are not at increased risk for hepatitis A because of their occupation 42.
  • Workers exposed to sewage. In the United States, no work-related outbreaks of hepatitis A have been reported among workers exposed to sewage. Studies on the incidence of clinical hepatitis A virus infection do not show an increased risk in workers exposed to sewage. People who work with sewage (e.g., plumbers) also are not at risk for hepatitis A virus infection 43.
  • Health-care personnel. Hepatitis A vaccine is not routinely recommended for health-care personnel, because health-care-associated hepatitis A virus transmission is rare. Health-care personnel should be encouraged to adhere to recommended infection control practices, standard precautions, and contact precautions for incontinent patients, including hand hygiene 44.
  • Child-care–center staff. Hepatitis A outbreaks in child-care centers are now rare in the United States, and routine vaccination of child-care–center staff is not warranted. Hepatitis A vaccination is recommended for all children at 1 year of age, including children attending child-care centers.

Should pre-vaccination testing be performed before administering hepatitis A vaccine?

To reduce the costs of vaccinating people who are already immune to hepatitis A, prevaccination testing is recommended only in certain persons, specific circumstances to reduce the costs of vaccinating people who are already immune to hepatitis A, including:

  • Persons who were born in geographic areas with high or intermediate prevalence of hepatitis A virus infection;
  • Older adolescents and adults in certain population groups (i.e., American Indians, Alaska Natives, and Hispanics); and
  • Adults in groups that have a high prevalence of infection (e.g., injection-drug users).

Pre-vaccination testing might also be warranted for older adults.

The decision to test should be based on 38:

  1. The expected prevalence of immunity,
  2. The cost of vaccination compared with the cost of serologic testing, and
  3. The likelihood that testing will not interfere with initiation of vaccination.

Additional information is available at: 31

Should post-vaccination testing be performed?

No. Postvaccination testing is not indicated because of the high rate of vaccine response among adults and children. In addition, not all testing methods approved for routine diagnostic use in the United States have the sensitivity to detect low, but protective, anti-hepatitis A (hepatitis A antibody) concentrations after vaccination. Additional information is available at 31.

How long does protection from hepatitis A vaccine last?

The exact duration of protection after vaccination is unknown. Anti-hepatitis A (hepatitis A antibody) has been shown to persist for at least 20 years in most people receiving the 2-dose series as infants <2 years of age 45, those vaccinated with a 3-dose series as young children (aged 3–6 years) 46 and adults receiving the entire vaccine series during adulthood 47. Detectable antibodies are estimated to persist for 40 years or longer based on mathematical modeling and anti-HAV kinetic studies 48.

Can hepatitis A vaccine be administered concurrently with other vaccines ?

Yes. Hepatitis B, diphtheria, poliovirus (oral and inactivated), tetanus, typhoid (oral and intramuscular), cholera, Japanese encephalitis, rabies, and yellow fever vaccines can be given at the same time that hepatitis A vaccine is given, but at a different injection site 49, 50, 51. In studies among young children, simultaneous administration of hepatitis A vaccine did not affect the immunogenicity or reactogenicity of diphtheria-tetanus-acellular pertussis; inactivated polio; measles, mumps, rubella (MMR); hepatitis B; and Haemophilus influenzae type b vaccines 52.

Can a patient receive the first dose of hepatitis A vaccine from one manufacturer and the second (last) dose from another manufacturer?

Yes. Results of several studies indicate that the response of adults administered hepatitis A vaccine according to a schedule that mixed the two single-antigen vaccines currently licensed in the United States was equivalent to that of adults vaccinated according to the licensed schedules with the single vaccine 53.

What should be done if an infant receives the first dose of hepatitis A vaccine at an age younger than 12 months?

Although no known harm is associated with giving hepatitis A vaccine to infants, the hepatitis A vaccine dose(s) administered prior to 12 months of age might result in a suboptimal immune response, particularly in infants with passively acquired maternal antibody 32. Therefore, hepatitis A vaccine dose(s) administered at <12 months of age are not considered valid doses.

The hepatitis A vaccine two-dose series should be initiated starting at least 6 months after the last invalid dose and when the child is at least 1 year of age.

What should be done if the second (last) dose of hepatitis A vaccine is delayed?

The second dose should be given as soon as possible. Even if the second does is delayed, the first dose does not need to be repeated.

What should be done if a traveler cannot receive hepatitis A vaccine?

Travelers who are allergic to a vaccine component, who elect not to receive vaccine, or who are aged <12 months should receive a single dose of immune globulin, which provides effective protection against Hepatitis A virus infection for up to 2 months depending on the dosage given.

Information on immune globulin dosing is available at 54

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 (IG) before traveling. Persons who travel to developing countries are at high risk for hepatitis A. Even those traveling to urban areas, staying in luxury hotels, and those reporting that they maintain good hand hygiene and are careful about what they drink and eat are at high risk. For more information on international travel and hepatitis A virus, see CDC’s travel page at 55 or ACIP updated recommendations on Prevention of Hepatitis A after Exposure to Hepatitis A Virus and in International Travelers at 35.

Hepatitis A Vaccine Side Effects

Some people have temporary soreness, redness and hardening of the skin at the injection site after having the hepatitis A vaccine.

A small, painless lump may also form, but it usually disappears quickly and is not a cause for concern.

Less common side effects include:

  • a slightly raised temperature
  • feeling unwell
  • tiredness
  • a headache
  • feeling sick
  • loss of appetite

HAVRIX ®

In studies of adults and children 2 years of age and older, the most common solicited adverse events were injection site soreness (56% of adults and 21% of children) and headache (14% of adults and less than 9% of children) 56.

In studies of children 11 to 25 months of age, the most frequently reported solicited local reactions were pain (32%) and redness (29%). Common solicited general adverse events were irritability (42%), drowsiness (28%), and loss of appetite (28%) 56.

VAQTA ®

The most common local adverse reactions and systemic adverse events (≥15%) reported in different clinical trials across different age groups when VAQTA was administered alone or concomitantly were 57:

  • Children — 12 through 23 months of age: injection-site pain/tenderness (37.0%), injection-site erythema (21.2%), fever (16.4% when administered alone, and 27.0% when administered concomitantly).
  • Children/Adolescents — 2 through 18 years of age: injection-site pain (18.7%).
  • Adults — 19 years of age and older: injection-site pain, tenderness, or soreness (67.0%), injection-site warmth (18.2%) and headache (16.1%).

TWINRIX ®

Following any dose of TWINRIX, the most common (≥10%) solicited injection site reactions were injection site soreness (35% to 41%) and redness (8% to 11%); the most common solicited systemic adverse events were headache (13% to 22%) and fatigue (11% to 14%) 58.

Hepatitis A Outbreak

For the current U.S. outbreaks among people who are homeless and/or people who use injection and non-injection drugs, Centers for Disease Control and Prevention (CDC) has provided interim outbreak-specific guidance on hepatitis A vaccine administration.

Post exposure prophylaxis is recommended for unvaccinated people who have been exposed to hepatitis A virus (HAV) in the last 2 weeks; those with evidence of previous vaccination do not require post exposure prophylaxis .

Post exposure prophylaxis consists of:

  • Hepatitis A vaccine for people aged 1-40 years
  • Hepatitis A virus-specific immunoglobulin (IG) for people outside of this age range. If immunoglobulin is not available, hepatitis A vaccine can be substituted

NOTE: CDC recommends that all children be vaccinated against hepatitis A at age 1 year. Parents or caregivers who are unsure if a child has been vaccinated should consult the child’s health-care provider to confirm vaccination status.

Hepatitis A diagnosis

To diagnose hepatitis A, your doctor may use many tools:

  • A medical history, which includes asking about your symptoms
  • A physical exam
  • Blood tests are used to look for signs of the hepatitis A virus in your body. A sample of blood is taken, usually from a vein in your arm. It’s sent to a laboratory for testing.

Hepatitis A Treatment

No specific treatment exists for hepatitis A. Your body will clear the hepatitis A virus on its own. In most cases of hepatitis A, the liver heals within six months with no lasting damage. The best way to recover is to rest, drink plenty of liquids, and eat healthy foods. Your doctor may also suggest medicines to help relieve symptoms. In more severe cases, you may need care in a hospital.

Hepatitis A treatment usually focuses on keeping you comfortable and controlling your signs and symptoms. You may need to 59:

  • Rest. Many people with hepatitis A infection feel tired and sick and have less energy.
  • Manage nausea. Nausea can make it difficult to eat. Try snacking throughout the day rather than eating full meals. To get enough calories, eat more high-calorie foods. For instance, drink fruit juice or milk rather than water. Drinking plenty of fluids is important to prevent dehydration if vomiting occurs.
  • Take painkillers, such as acetaminophen (paracetamol) or ibuprofen, if you have any aches and pains – how much you can take depends on how well your liver is working (ask your doctor for advice)
  • Reduce itching by maintaining a cool, well-ventilated environment, wearing loose clothing and avoiding hot baths or showers – your doctor may recommend using an antihistamine in severe cases.
  • Avoid alcohol and use medications with care. Your liver may have difficulty processing medications and alcohol. If you have hepatitis, don’t drink alcohol. It can cause more liver damage. Talk to your doctor about all the medications you take, including over-the-counter drugs.

Hepatitis A lifestyle and home remedies

You can take steps to reduce the risk of passing hepatitis A to others.

  • Avoid sexual activity. Avoid all sexual activity if you have hepatitis A. Many kinds of sexual activity can spread the infection to your partner. Condoms don’t offer adequate protection.
  • Wash your hands thoroughly after using the toilet and changing diapers. Scrub vigorously for at least 20 seconds and rinse well. Dry your hands with a disposable towel.
  • Don’t prepare food for others while you’re actively infected. You can easily pass the infection to others.

What should I eat and drink if I have hepatitis A?

If you have hepatitis A, you should eat a balanced, healthy diet. Talk with your doctor about healthy eating. You should also avoid alcohol because it can cause more liver damage.

Hepatitis A prognosis

The outcomes for most patients with hepatitis A virus are excellent. After an infection, long term immunity is common and unlike the other viral hepatitis infections, recurrence of symptoms is rare. Death is rare but may occur in older individuals or those with underlying liver disease. In the US, there are about a hundred deaths from hepatitis A virus every year. Rarely in children with fulminant disease, liver transplant has been undertaken. The most important prognostic factor is age; the older the individual, the more likely that an adverse reaction or event may occur. Long term complications are very rare.

References
  1. Hepatitis A Information. https://www.cdc.gov/hepatitis/hav/havfaq.htm
  2. Viral Hepatitis Surveillance Report 2019. https://www.cdc.gov/hepatitis/statistics/2019surveillance/HepA.htm
  3. Hepatitis A Questions and Answers for Health Professionals. https://www.cdc.gov/hepatitis/hav/havfaq.htm
  4. Krugman S, Giles JP, Hammond J. Infectious hepatitis. Evidence for two distinctive clinical, epidemiological, and immunological types of infection. Jama. 1967;200(5):365-373.
  5. Griffin DW, Donaldson KA, Paul JH, Rose JB. Pathogenic human viruses in coastal waters. Clinical microbiology reviews. 2003;16(1):129-143.
  6. Peterson DA, Hurley TR, Hoff JC, Wolfe LG. Effect of chlorine treatment on infectivity of hepatitis A virus. Appl Environ Microbiol. 1983;45(1):223-227.
  7. Koff RS. Clinical manifestations and diagnosis of hepatitis A virus infection. Vaccine. 1992;10 Suppl 1:S15-17.
  8. Purcell RH. Relative infectivity of hepatitis A virus by the oral and intravenous routes in 2 species of nonhuman primates. The Journal of infectious diseases. 2002;185:1668-1771.1. Purcell RH. Relative infectivity of hepatitis A virus by the oral and intravenous routes in 2 species of nonhuman primates. The Journal of infectious diseases. 2002;185:1668-1771.
  9. Tassopoulos NC, Papaevangelou GJ, Ticehurst JR, Purcell RH. Fecal excretion of Greek strains of hepatitis A virus in patients with hepatitis A and in experimentally infected chimpanzees. The Journal of infectious diseases. 1986;154(2):231-237.
  10. https://www.cdc.gov/hepatitis/statistics/2015surveillance/index.htm
  11. Fiore AE. Hepatitis A transmitted by food. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 2004;38(5):705-715.
  12. Halliday ML, Kang LY, Zhou TK, et al. An epidemic of hepatitis A attributable to the ingestion of raw clams in Shanghai, China. The Journal of infectious diseases. 1991;164(5):852-859.
  13. https://www.cdc.gov/disasters/floods/after.html
  14. Cuthbert JA. Hepatitis A: old and new. Clin Microbiol Rev 2001; 14: 36-58.
  15. The global prevalence of hepatitis A virus infection and susceptibility. https://www.who.int/publications/i/item/the-global-prevalence-of-hepatitis-a-virus-infection-and-susceptibility
  16. Iorio N, John S. Hepatitis A. [Updated 2021 Jul 19]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459290
  17. Rac MW, Sheffield JS. Prevention and management of viral hepatitis in pregnancy. Obstetrics and Gynecology Clinics of North America. 2014;41(4):573–592.
  18. Robertson BH1, Jansen RW, Khanna B, Totsuka A, Nainan OV, Siegl G, Widell A, Margolis HS, Isomura S, Ito K, et al. Genetic relatedness of hepatitis A virus strains recovered from different geographical regions. J Gen Virol. 1992 Jun;73 ( Pt 6):1365-77.
  19. Ajmera V1, Xia G, Vaughan G, Forbi JC, Ganova-Raeva LM, Khudyakov Y, Opio CK, Taylor R, Restrepo R, Munoz S, Fontana RJ, Lee WM; Acute Liver Failure Study Group. What factors determine the severity of hepatitis A-related acute liver failure J Viral Hepat. 2011 Jul;18(7):e167-74.
  20. Nainan OV, Armstrong GL, Han XH, Williams I, Bell BP, Margolis HS. Hepatitis a molecular epidemiology in the United States, 1996-1997: sources of infection and implications of vaccination policy. J Infect Dis. 2005 Mar 15; 191(6):957-63.
  21. Collier MG, Khudyakov YE, Selvage D, Adams-Cameron M, Epson E, Cronquist A, Jervis RH, Lamba K, Kimura AC, Sowadsky R, Hassan R, Park SY, Garza E, Elliott AJ, Rotstein DS, Beal J, Kuntz T, Lance SE, Dreisch R, Wise ME, Nelson NP, Suryaprasad A, Drobeniuc J, Holmberg SD, Xu F; Hepatitis A Outbreak Investigation Team. Outbreak of hepatitis A in the USA associated with frozen pomegranate arils imported from Turkey: an epidemiological case study. Lancet Infect Dis. 2014 Oct; 14(10):976-81.
  22. Lednar WM, Lemon SM, Kirkpatrick JW, Redfield RR, Fields ML, Kelley PW. Frequency of illness associated with epidemic hepatitis A virus infections in adults. American journal of epidemiology. 1985;122(2):226-233.
  23. Tong MJ, el-Farra NS, Grew MI. Clinical manifestations of hepatitis A: recent experience in a community teaching hospital. The Journal of infectious diseases. 1995;171 Suppl 1:S15-18.
  24. Handwashing: Clean Hands Save Lives. https://www.cdc.gov/handwashing/show-me-the-science.html
  25. Nelson NP. Updated Dosing Instructions for Immune Globulin (Human) GamaSTAN S/D for Hepatitis A Virus Prophylaxis. MMWR Morb Mortal Wkly Rep 2017;66:959–960. DOI: http://dx.doi.org/10.15585/mmwr.mm6636a5
  26. https://www.fda.gov/media/86789/download
  27. Important change in prescribing information immune globulin (human): GamaSTAN S/D. https://www.hypermunes.com/documents/24720443/24803488/Healthcare+Provider+Letter+GamaSTAN+SD+Revised+Dosage+July+7+2017_with+LIT+CODE.pdf/b831e517-9d0b-472c-b5b5-719f5bb5e47c
  28. Hadler SC, Webster HM, Erben JJ, Swanson JE, Maynard JE. Hepatitis A in day-care centers. A community-wide assessment. The New England journal of medicine. 1980;302(22):1222-1227.
  29. Carl M, Francis DP, Maynard JE. Food-borne hepatitis A: recommendations for control. The Journal of infectious diseases. 1983;148(6):1133-1135.
  30. Millard J, Appleton H, Parry JV. Studies on heat inactivation of hepatitis A virus with special reference to shellfish. Part 1. Procedures for infection and recovery of virus from laboratory-maintained cockles. Epidemiol Infect. 1987;98(3):397-414.
  31. https://www.cdc.gov/mmwr/preview/mmwrhtml/rr5507a1.htm
  32. Letson GW, Shapiro CN, Kuehn D, et al. Effect of maternal antibody on immunogenicity of hepatitis A vaccine in infants. J Pediatr 2004;144:327–32.
  33. https://wwwnc.cdc.gov/travel/yellowbook/2018/infectious-diseases-related-to-travel/hepatitis-a for more information
  34. https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5836a4.htm
  35. https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5641a3.htm
  36. https://www.cdc.gov/vaccines/schedules/hcp/imz/adult-conditions.html
  37. Moro PL, Museru OI, Niu M, Lewis P, Broder K. Reports to the Vaccine Adverse Event Reporting System after hepatitis A and hepatitis AB vaccines in pregnant women. Am J Obstet Gynecol. 2014 Jun;210(6):561.e1-6.
  38. Ott JJ, Wiersma ST. Single-dose administration of inactivated hepatitis A vaccination in the context of hepatitis A vaccine recommendations. Int J Infect Dis. 2013 Nov;17(11):e939-44.
  39. Nelson NP. Updated Dosing Instructions for Immune Globulin (Human) GamaSTAN S/D for hepatitis A virus prophylaxis. MMWR 2017;66(36):959–60.
  40. Klamroth R, Groner A, Simon TL. Pathogen inactivation and removal methods for plasma-derived clotting factor concentrates. Transfusion 2014;54(5):1406–17.
  41. Groner A. Pathogen safety of plasma-derived products—Haemate P/Humate-P. Haemophilia 2008;14 Suppl 5:54–71.
  42. Fiore AE. Hepatitis A transmitted by food. Clinical Infect Dis 2004;38(5):705–15.
  43. Glas C, Hotz P, Steffen R. Hepatitis A in workers exposed to sewage: a systematic review. Occup Environ Med 2001;58(12):762–8. Review.
  44. Siegel JD, Rhinehart E, Jackson M, Chiarello L. 2007 Guideline for isolation precautions preventing transmission of infectious agents in health care settings. Centers for Disease Control and Prevention. https://www.cdc.gov/infectioncontrol/guidelines/isolation/index.html
  45. Spradling PR, Bulkow LR, Negus SE, Homan C, Bruce MG, McMahon BJ. Persistence of seropositivity among persons vaccinated for hepatitis A during infancy by maternal antibody status: 15-year follow-up. Hepatology 2016;63(3):703–11.
  46. Mosites E, Gounder P, Snowball M, et al. Hepatitis A vaccine immune response 22 years after vaccination. J Medical Virol 2018;90(8):1418–22.
  47. Theeten H, Van Herck K, Van Der Meeren O, Crasta P, Van Damme P, Hens N. Long-term antibody persistence after vaccination with a 2-dose Havrix™ (inactivated hepatitis A vaccine): 20 years of observed data, and long-term model-based predictions. Vaccine 2015;33(42):5723–7.
  48. Hens N, Habteab Ghebretinsae A, Hardt K, Van Damme P, Van Herck K. Model based estimates of long-term persistence of inactivated hepatitis A vaccine-induced antibodies in adults. Vaccine. 2014;32(13):1507-1513.
  49. Clemens R, Safary A, Hepburn A, Roche C, Stanbury WJ, Andre FE. Clinical experience with an inactivated hepatitis A vaccine. The Journal of infectious diseases. 1995;171 Suppl 1:S44-49.
  50. Ambrosch F, Andre FE, Delem A, et al. Simultaneous vaccination against hepatitis A and B: results of a controlled study. Vaccine. 1992;10 Suppl 1:S142-145.
  51. Jong EC, Kaplan KM, Eves KA, Taddeo CA, Lakkis HD, Kuter BJ. An open randomized study of inactivated hepatitis A vaccine administered concomitantly with typhoid fever and yellow fever vaccines. Journal of travel medicine. 2002;9(2):66-70.
  52. Usonis V, Meriste S, Bakasenas V, et al. Immunogenicity and safety of a combined hepatitis A and B vaccine administered concomitantly with either a measles-mumps-rubella or a diphtheria-tetanus-acellular pertussis-inactivated poliomyelitis vaccine mixed with a Haemophilus influenzae type b conjugate vaccine in infants aged 12-18 months. Vaccine. 2005;23(20):2602-2606.
  53. Connor BA, Phair J, Sack D, et al. Randomized, double-blind study in healthy adults to assess the boosting effect of Vaqta or Havrix after a single dose of Havrix. Clinical infectious diseases: an official publication of the Infectious Diseases Society of America. 2001;32(3):396-401.
  54. https://www.cdc.gov/mmwr/volumes/66/wr/mm6636a5.htm?s_cid=mm6636a5_e
  55. https://wwwnc.cdc.gov/travel/yellowbook/2018/infectious-diseases-related-to-travel/hepatitis-a
  56. https://www.fda.gov/downloads/BiologicsBloodVaccines/Vaccines/ApprovedProducts/UCM224555.pdf
  57. https://www.fda.gov/downloads/BiologicsBloodVaccines/Vaccines/ApprovedProducts/UCM110049.pdf
  58. https://www.fda.gov/downloads/BiologicsBloodVaccines/Vaccines/ApprovedProducts/UCM110079.pdf
  59. Hepatitis A. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/hepatitis-a/diagnosis-treatment/drc-20367055
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