Outbreak-specific considerations for hepatitis A vaccine administration

The hepatitis A vaccine is the best way to prevent HAV infection
The following groups are at highest risk for acquiring HAV infection or developing serious complications from HAV infection in these outbreaks and should be offered the hepatitis A vaccine in order to prevent or control an outbreak:

  • People who use drugs (injection or non-injection)
  • People experiencing unstable housing or homelessness
  • Men who have sex with men (MSM)
  • People who are currently or were recently incarcerated
  • People with chronic liver disease, including cirrhosis, hepatitis B, or hepatitis C

During the current hepatitis A outbreak, clinicians and vaccinators can consider the following when prescribing and administering hepatitis A vaccine:

One dose of hepatitis A vaccine

One dose of single-antigen hepatitis A vaccine has been shown to successfully control outbreaks of hepatitis A.(1,2)

Additional information on duration of protection is available at: Hepatitis A Questions and Answers for Health Professionals

TWINRIX® for pre-exposure prophylaxis

TWINRIX® is licensed for use in persons aged >18 years and is a combined hepatitis A (HAVRIX) and hepatitis B vaccine (ENGERIX-B®).   ACIP recommends the hepatitis A and hepatitis B vaccine for some of the affected populations (e.g., persons at risk for both hepatitis A and B infection and likely to complete the 3-dose vaccine series).

After 3 doses of TWINRIX®, antibody responses to both antigens are equivalent to responses seen after the single antigen vaccines are administered separately on standard schedules.

Seroconversion and Seroprotection Rates in Worldwide Clinical Trials TWINRIX Dose N % Seroconversion for Hepatitis A a % Seroprotection for Hepatitis B b
1 1,587 93.8 30.8
2 1,571 98.8 78.2
3 1,551 99.9 98.5

aAnti-HAV titer ≥assay cut-off: 20 mIU/mL (HAVAB Test) or 33 mIU/mL (ENZYMUN-TEST®).
bAnti-HBsAg titer ≥10 mIU/mL (AUSAB® Test).

If TWINRIX® is given during an outbreak, vaccinators should ensure everyone receiving TWINRIX® knows the importance of receiving all three doses to get maximum protection from hepatitis A and hepatitis B.

TWINRIX® for post-exposure prophylaxis

TWINRIX® is not recommended for post-exposure prophylaxis. TWINRIX® contains 720 EL.U. of hepatitis A antigen, which is half of the HAVRIX® adult dose. No data are available for use of TWINRIX® for post-exposure prophylaxis, and therefore is not recommended for post-exposure prophylaxis.

Hepatitis A vaccines should only be administered in age-appropriate doses

Administering 2-doses of 25 U VAQTA® or 2-doses of 720 EL.U. HAVRIX® to persons aged >18 years in place of one adult dose is not an ACIP recommendation and is not included as a method for dosage and administration in the manufacturers’ package inserts. Hepatitis A vaccines should only be administered in the age-appropriate doses.

  • VAQTA® (manufactured by Merck & Co., Inc) is licensed in two formulations. Persons aged 12 months–18 years should receive 25 U per dose in a 2-dose schedule; persons aged >18 years should receive 50 U per dose in a 2-dose schedule.
  • HAVRIX® (manufactured by GlaxoSmithKline) is available in two formulations: for persons aged 12 months–18 years, 720 EL.U. per dose in a 2-dose schedule; and for persons aged >18 years, 1,440 EL.U. per dose in a 2-dose schedule.
Pre-vaccination serological testing

Pre-vaccination serological testing is not required in order to administer hepatitis A vaccine.  Vaccination of a person who is immune because of previous infection does not increase the risk for adverse events from vaccination. Vaccinations should not be postponed if vaccination history cannot be obtained or records are unavailable.

In populations that are expected to have high rates of previous HAV infection, vaccination history should be obtained where feasible. Pre-vaccination testing may be considered to reduce costs by not vaccinating persons who are already immune.

Additional information on pre-vaccination serological testing is available at: Hepatitis A Questions and Answers for Health Professionals  or ACIP General Best Practice Guidelines for Immunization [PDF – 197 pages].

Current Advisory Committee on Immunization Practices (ACIP) Recommendations

1. 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. doi: 10.1016/j.ijid.2013.04.012. Epub 2013 Jun 21. Review. PubMed PMID: 23791857.

2. McMahon BJ, Beller M, Williams J, Schloss M, Tanttila H, Bulkow L. A program to control an outbreak of hepatitis A in Alaska by using an inactivated hepatitis A vaccine. Arch Pediatr Adolesc Med. 1996 Jul;150(7):733-9. PubMed PMID: 8673200.