Issue 1,509: August 10, 2020
Ask the Experts: IAC Answers Questions about Hepatitis A Vaccination and a Few Other Topics
As an additional service to IAC Express readers, we periodically publish special editions such as this one, providing you with new and updated Ask the Experts questions and answers from IAC experts. This issue includes Q&As about hepatitis A vaccination based on recently updated ACIP recommendations, as well as a few additional questions on other topics.
You can find all of these questions and answers, plus more than a thousand others about vaccines and vaccine administration, on our Ask the Experts gateway page at
www.immunize.org/askexperts.
IAC's team of experts includes Kelly L. Moore, MD, MPH (team lead); Carolyn Bridges, MD, FACP; William Atkinson, MD, MPH; and Deborah Wexler, MD.
Hepatitis A vaccination questions
Additional questions
Hepatitis A vaccination questions
Q: How common is HAV infection in the United States?
A: In 2017, 3,366 acute clinical cases were reported to CDC's surveillance system. This number is an underestimate of the actual number of infections: CDC estimates that about 6,700 occurred in 2017. Historically, acute hepatitis A rates vary cyclically, with nationwide increases every 10–15 years. The last peak was in 1995; rates of hepatitis A decreased by 95% from 1995 to 2011, then increased by 140% from 2011 to 2017.
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Q: Do people die from hepatitis A?
A: Yes. Death as a result of fulminant hepatic failure is rare, however, older age (over 40 years) and preexisting chronic liver disease increases the risk of severe disease and death from hepatitis A. As of June 2020, the person-to-person multistate outbreak that has infected over 33,000 people since 2016 in the United States has disproportionately affected adults with chronic liver disease and other health problems related to drug use and unstable housing. To date, approximately 60% of cases reported as part of that outbreak have been hospitalized and 1% have died.
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Q: Who is most at risk for acquiring HAV infection?
A: People who are at increased risk for acquiring HAV infection include the following:
- Travelers to countries that have high or intermediate endemicity of HAV infection
- Men who have sex with men (MSM)
- Users of injection and noninjection drugs (in other words, all who use illegal drugs)
- People with occupational risk of exposure (non-human primates or researchers handling hepatitis A virus)
- People who anticipate close contact with an international adoptee coming from a country with high or intermediate endemicity of HAV infection
- People living with HIV infection
- People experiencing homelessness, including temporary shelters and other unstable living arrangements
- People living in group settings for those with developmental disabilities and other settings where hygiene is difficult to maintain
- People who are incarcerated
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Q: Who is recommended to receive HepA vaccine?
A: The Advisory Committee on Immunization Practices (ACIP) recommends routine HepA vaccination for the following groups:
- All children at age 1 year (12–23 months)
- All children and adolescents age 2 through 18 years who have not previously received HepA should be vaccinated (i.e., routine catch-up vaccination) [2020]
- People living with HIV infection [2020]
- Travelers age 12 months and older to areas of the world with intermediate or high HAV endemicity. Low endemicity regions include the United States, Canada, Western Europe, Japan, New Zealand, and Australia. For more information, see the CDC travel health website for current information about specific countries at www.cdc.gov/travel or the CDC Yellow Book (wwwnc.cdc.gov/travel/yellowbook/2020/travel-related-infectious-diseases/hepatitis-a). When in doubt, vaccinate.
- Infants age 6 through 11 months traveling outside the United States should receive 1 dose when protection against HAV infection is recommended. The travel dose does not count toward the routine HepA series which should be initiated at age 1 year with the appropriate dose and schedule.
- Men who have sex with men
- Users of illegal drugs, injectable or noninjectable
- People who are homeless or in unstable living arrangements, including shelters
- Previously unvaccinated people who anticipate having close personal contact with an international adoptee from a country of high or intermediate endemicity during the first 60 days following the adoptee's arrival in the U.S.
- People who work with nonhuman primates or with HAV in a research laboratory setting
- People with chronic liver disease (including but not limited to people with hepatitis B infection, hepatitis C infection, cirrhosis, fatty liver disease, alcoholic liver disease, autoimmune hepatitis, or an ALT or AST level persistently greater than twice the upper limit of normal)
- Any person who wishes to be immune to hepatitis A
HepA vaccination is not routinely recommended for healthcare personnel, food handlers, sewage workers, or day care providers because there is no evidence that their occupational risks of HAV exposure are significantly higher than the general population. However, any person who desires protection from HAV infection may be vaccinated.
For details about CDC recommendations for the prevention of hepatitis A, see the 2020 recommendations of the Advisory Committee on Immunization Practices (ACIP): www.cdc.gov/mmwr/volumes/69/rr/pdfs/rr6905a1-H.pdf.
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Q: I thought people with clotting factor disorders were at risk for hepatitis A due to their regular use of blood products. Why did ACIP decide to stop recommending routine vaccination of people with clotting factor disorders?
A: People with clotting factor disorders were originally recommended to receive hepatitis A vaccine (HepA) in 1996. At that time, the process used to make clotting factor supplements did not reliably inactivate hepatitis A viruses and recipients of these products had an increased risk of HAV infection. Modern blood donor screening and virus reduction steps have drastically reduced that risk. In addition, more than 80% of people with clotting factor disorders now receive recombinant clotting factor concentrates that are sterilized and have no risk of HAV transmission. As a result of these factors, people with clotting factor disorders now have no greater risk of hepatitis A than the general population and are no longer recommended to receive HepA vaccine unless it is otherwise indicated.
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Q: What are the recommendations for postexposure prophylaxis (PEP) for hepatitis A?
A: In 2020, CDC published revised recommendations for hepatitis A postexposure prophylaxis (PEP). Please see the complete PEP recommendations at www.cdc.gov/mmwr/volumes/69/rr/pdfs/rr6905a1-H.pdf, with special attention to Table 4 on page 19 and Appendix B: Provider Guidance on Risk Assessment for Hepatitis A Postexposure Prophylaxis, beginning on page 36.
Healthy people who have completed the HepA vaccination series at any time do not need additional PEP if they are exposed to HAV. People who have recently been exposed to HAV and who have not received HepA vaccine previously should receive PEP as soon as possible, within 2 weeks of exposure.
People age 12 months and older exposed to HAV within the past 14 days and who have not previously completed the HepA vaccine series should receive a single dose of HepA vaccine as soon as possible. In addition to vaccine, immune globulin (IG; 0.1 mL/kg) may be administered to people older than age 40 years depending on the providers’ risk assessment. For long-term immunity, the HepA vaccine series should be completed with a second dose at least 6 months after the first dose. However, the second dose is not necessary for PEP. A second dose should not be administered sooner than 6 calendar months after the first dose, regardless of HAV exposure risk.
People age 12 months or older who are immunocompromised or have chronic liver disease, and who have been exposed to HAV within the past 14 days and have not previously completed the HepA vaccination series, should receive both IG (0.1 mL/kg) and HepA vaccine at the same visit in a different anatomic site (for example, separate limbs) as soon as possible after exposure. For long-term immunity, the HepA vaccination series should be completed with a second dose at least 6 months after the first dose. However, the second dose is not necessary for PEP. A second dose should not be administered sooner than 6 calendar months after the first dose, regardless of HAV exposure risk.
People with HIV infection develop protective levels of antibody more slowly and are less likely to develop protective antibody levels after vaccination with HepA, especially if their CD4+ count is low at the time of vaccination. Protection following vaccination of a person with HIV may wane over time. Vaccine should be administered if the exposed individual is not fully vaccinated; however, CDC also advises clinicians to consider administering IG PEP to an individual with HIV after a high-risk exposure (such as a household or sexual contact) even if the individual has been fully vaccinated.
Twinrix contains half the amount of hepatitis A antigen as a standard single-dose adult HepA vaccine. Twinrix should not be used for PEP, but may be used to confer protection to at-risk but not yet exposed persons during an outbreak.
Infants younger than age 12 months and persons for whom vaccine is contraindicated should receive IG (0.1 mL/kg) instead of HepA vaccine as soon as possible and within 2 weeks of exposure. MMR and varicella vaccines should not be administered sooner than 6 months after IG administration in order to avoid possible IG interference with the effectiveness of MMR and varicella vaccines.
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Q: ACIP now recommends routine hepatitis A vaccination for people experiencing homelessness. Can you provide a definition of "experiencing homelessness"?
A: The 2020 ACIP recommendations for the prevention of hepatitis A define a person experiencing homelessness as 1) a person who lacks housing (regardless of whether the person is a member of a family), including a person whose primary residence during the night is a supervised public or private facility (e.g., shelter) that provides temporary living accommodations and a person who is a resident in transitional housing, 2) a person without permanent housing who might: live on the streets, stay in a shelter, mission, single-room occupancy facility, abandoned building, vehicle, or any other unstable or nonpermanent situation, or 3) who is “doubled up,” a term that refers to a situation where persons are unable to maintain their housing situation and are forced to stay with a series of friends or extended family members. In addition, previously homeless persons who are to be released from a prison or a hospital might be considered homeless if they do not have a stable housing situation to which they can return. The instability of a person’s living arrangements is critical to the definition of homelessness.
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Q: Some people on my team are worried about initiating the HepA vaccine series in people who are homeless because we may not be able to complete the series or keep up with their records over time. How much of a concern is this?
A: While a complete series of HepA is recommended for long-term protection, even a single dose of HepA vaccine has been demonstrated to provide protection against hepatitis A for more than 10 years and can prevent or control outbreaks of hepatitis A. People who are experiencing homelessness may have difficulty protecting themselves from exposure to HAV in other ways because of their living conditions. They should be vaccinated when possible and provided a record of immunization. Reporting the HepA vaccination to a state immunization information system also can facilitate immunization assessment at future healthcare encounters.
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Q: Why is hepatitis A vaccination recommended (and IG not recommended) for infant travelers age 6 through 11 months at risk of exposure to HAV?
A: Because of measles. Measles is highly communicable and poses a serious threat to the health of unvaccinated infants. For this reason, all infants age 6 through 11 months who travel internationally are recommended to receive a dose of measles, mumps, and rubella vaccine (MMR) to reduce the risk of measles infection during travel.
The antibodies in immune globulin (IG) typically used to prevent HAV infection in infants before the first birthday can interfere with the effectiveness of MMR vaccine. An infant who is given IG should not be vaccinated with MMR or varicella vaccines for at least 6 months after IG administration. If an infant age 6 through 11 months is traveling to a destination where protection from infection with HAV is desired, ACIP recommends off-label use of HepA vaccine (not IG) in addition to MMR. The HepA and MMR doses administered before the first birthday do not count toward the routine vaccination series of either vaccine: these infant travelers will still need two doses of HepA and two doses of MMR when age appropriate.
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Q: A child in my practice was given hepatitis A IG (GamaSTAN, Grifols) when she was 10 months old after her mother tested positive for hepatitis A. She’s scheduled for her 12-month-old well-child visit. Will this affect her vaccination schedule?
A: Yes. IG may be given any time before or after inactivated vaccines. However, the antibodies in IG may interfere with the effectiveness of certain live-virus vaccines, such as measles, mumps, and rubella (MMR) and varicella vaccines. CDC recommends waiting at least 6 months from the date of IG administration before administering MMR and varicella vaccines.
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Q: Which people should get GamaSTAN (IG) for prevention of hepatitis A?
A: Please see details of the recommendations for the use of IG for the prevention of hepatitis A provided in Table 4 (page 19) and Appendices A and B of the 2020 ACIP recommendations for the prevention of hepatitis A infection: www.cdc.gov/mmwr/volumes/69/rr/pdfs/rr6905a1-H.pdf.
Below is a brief summary of the recommendations:
Preexposure prophylaxis with IG for travel to areas of intermediate or high hepatitis A endemicity:
- Infants younger than age 6 months and other travelers for whom HepA vaccine is declined or contraindicated
- Previously unvaccinated people with chronic liver disease vaccinated within 2 weeks of departure may consider IG in addition to vaccination, based upon the clinician’s risk assessment
- Previously unvaccinated people who are immunocompromised may consider IG in addition to vaccination, based upon the clinician’s risk assessment
- Previously unvaccinated people who are over age 40 years and vaccinated within 2 weeks of departure may consider IG in addition to vaccination, based upon the clinician’s risk assessment
Postexposure prophylaxis with IG within 2 weeks after exposure to hepatitis A virus (HAV):
- Infants under age 12 months
- Previously unvaccinated immunocompromised adults (including HIV+), in addition to vaccination
- Previously unvaccinated adults with chronic liver disease, in addition to vaccination
- Previously unvaccinated adults over age 40 years, consider IG in addition to vaccination, based upon clinician risk assessment
- People with HIV infection, previously vaccinated, consider IG following a high-risk exposure (household or sexual contact), based upon clinician risk assessment
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Q: Can pregnant women receive hepatitis A vaccine?
A: Yes. The ACIP recommends that pregnant women at risk for HAV infection during pregnancy or at risk for a severe outcome from HAV infection should be vaccinated during pregnancy if not previously vaccinated. Pregnant women should be vaccinated for the same indications as non-pregnant women. For additional information, see page 20 of the recommendations: www.cdc.gov/mmwr/volumes/69/rr/pdfs/rr6905a1-H.pdf.
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Q: Can HepA vaccine be given to immunocompromised people?
A: Yes. All people age 1 year or older living with HIV infection should be vaccinated against hepatitis A if they have not been vaccinated, regardless of their CD4+ count.
If any immunocompromised person has a risk factor that places them at increased risk of hepatitis A (e.g., international travel, drug use), they should be vaccinated with HepA vaccine.
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Q: I have a child who was given her second dose of hepatitis A vaccine 4 months after the first dose. Does it need to be repeated, and if so, when?
A: The second dose was given more than 4 days before the minimum interval of 6 calendar months, so it is considered invalid and should be repeated. The repeat dose should be administered the proper minimum interval (6 months) after the invalid dose. If this repeat dose is inadvertently given less than 6 months after the invalid dose, it does not need to be repeated again as long as the interval between the initial HepA vaccine and the most recent dose is at least 6 calendar months.
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Additional questions
Q: Can I give a recombinant zoster vaccine (RZV, Shingrix, GSK) at the same time as a tuberculin skin test?
A: Yes. Shingrix is not a live virus vaccine and does not interfere with the tuberculin skin test (TST): it may be administered any time before or after a TST. Administration of a live virus vaccine can interfere with a tuberculin skin test (TST). If the TST is not administered on the same day as a live virus vaccine, the TST should be delayed until 4–6 weeks after the vaccination.
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Q: Can the Shingrix vaccine cause shingles?
A: No. Shingrix contains only a small part of the herpes zoster virus and does not contain any live herpes zoster virus.
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Q: Since the 23-valent pneumococcal polysaccharide vaccine (PPSV23, Pneumovax, Merck) is recommended for all adults who smoke, should adults who vape nicotine, but do not smoke cigarettes, be vaccinated too?
A: No. ACIP does not identify people who use nicotine vaping products as being at increased risk for pneumococcal disease or as being in a risk group recommended for vaccination.
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