Hepatitis A and B vaccine

Twinrix is a vaccine against hepatitis A and hepatitis B, manufactured by GlaxoSmithKline Biologicals. The full generic name is hepatitis A inactivated & hepatitis B (recombinant) vaccine.[1] Twinrix is administered over three doses.

Hepatitis A and B vaccine
Combination of
Hepatitis A vaccineVaccine
Hepatitis B vaccineVaccine
Clinical data
Trade namesTwinrix, Ambirix, Twinrix Junior, others
AHFS/Drugs.comFDA Professional Drug Information
License data
Pregnancy
category
  • AU: B2
  • US: C (Risk not ruled out)
    Routes of
    administration    		Intramuscular injection
    ATC code
    Legal status
    Legal status
    Identifiers
    CAS Number
    ChemSpider
    • none

    The name was created because it is a mixture of two earlier vaccines — Havrix, an inactivated-virus Hepatitis A vaccine, and Engerix-B, a recombinant Hepatitis B vaccine. Twinrix first entered the market in early 1997.

    In the United States, Twinrix is approved by the Food and Drug Administration (FDA) for those aged 18 and older.[2] In some countries outside the United States, notably Canada and Europe, Twinrix is known as Twinrix Adult or Ambirix and a pediatric formulation, called Twinrix Junior or Twinrix Paediatric, is available.[3][4][5][6][7][8]

    Administration schedule

    Routine Twinrix vaccination is administered by intramuscular injection in the deltoid area using a schedule of three separate doses at 0, 1, and 6 months ([minimum intervals: 4 weeks between doses 1 and 2, 5 months between doses 2 and 3]).[9][10] In some circumstances, an accelerated dosing schedule of 0, 7 and 21 to 30 days followed by a booster at 12 months can be used and was shown to have similar efficacy as the traditional schedule.[11]

    Efficacy

    The U.S. Centers for Disease Control and Prevention (CDC) reports that clinical trials found the following levels of protection against Hepatitis A and Hepatitis B one month after each dose:[2]

    A: 93.8%, 98.8%, 99.9%
    B: 30.8%, 78.2%, 98.5%

    GlaxoSmithKline claims that its studies found 70% of subjects had antibodies against hepatitis B a month after just the first dose, however.[3]

    Twinrix should not be used for postexposure prophylaxis, because no data are available on the efficacy of combination vaccine for prophylaxis after exposure to HAV.[12]

    See also

    References
    1. "Twinrix". Food and Drug Administration (FDA). 24 April 2019. Retrieved 22 September 2019.
    2. "FDA approval for a combined hepatitis A and B vaccine" (PDF). MMWR Morb. Mortal. Wkly. Rep. 50 (37): 806–7. September 2001. PMID 11785573. Lay summary.
    3. "Twinrix Adult Vaccine SmPC". Datapharm. 8 October 2018.
    4. "Twinrix Paediatric Vaccine SmPC". Datapharm. 8 October 2018.
    5. "Ambirix SmPC". Datapharm. 5 November 2018.
    6. "Hepatitis A Vaccine: Canadian Immunization Guide". Public Health Agency of Canada. 2018-03-13. Retrieved 22 September 2019.
    7. "Twinrix (720/20)". The Australian Immunisation Handbook. 4 June 2018. Retrieved 22 September 2019. Lay summary.
    8. "Twinrix Junior (360/10)". The Australian Immunisation Handbook. 4 June 2018. Retrieved 22 September 2019. Lay summary.
    9. "Package Insert - TWINRIX" (PDF). Food and Drug Administration (FDA). Retrieved 22 September 2019.
    10. "Recommended Adult Immunization Schedule for ages 19 years or older, United States, 2019". Centers for Disease Control and Prevention (CDC). 5 February 2019. Retrieved 22 September 2019. This article incorporates text from this source, which is in the public domain.
    11. "Notice to Readers: FDA Approval of an Alternate Dosing Schedule for a Combined Hepatitis A and B Vaccine (Twinrix)" (PDF). Centers for Disease Control and Prevention (CDC). 12 October 2007. Retrieved 22 September 2019. Lay summary.
    12. "Hepatitis A - Chapter 4 - 2020 Yellow Book - Travelers' Health". Centers for Disease Control and Prevention (CDC). 1 July 2019. Retrieved 22 September 2019. This article incorporates text from this source, which is in the public domain.
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