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Hepatitis Health Center

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Combination Vaccine for Hepatitis A and B


Generic Name Brand Name
hepatitis A inactivated and hepatitis B recombinant vaccine Twinrix

How It Works

Twinrix is a vaccine that provides active immunity against both the hepatitis A and hepatitis B viruses. It is given in a series of 3 injections on the same schedule as the hepatitis B vaccine: an initial dose followed by doses at 1 month and 6 months. It can also be given in 4 doses, with the initial dose followed by doses at 7 days, 21 to 30 days, and 12 months.

Why It Is Used

This combination vaccine can prevent both hepatitis A virus (HAV) and hepatitis B virus (HBV) infection with only one series of injections. People get the vaccines together rather than separately. The U.S. Food and Drug Administration (FDA) has approved its use only for people age 18 or older who are at risk of infection with HAV and HBV. These include people who:

  • Will travel to areas with moderate to high rates of HAV and HBV. These include Africa, the Caribbean, Central America, South America, Mexico, South and Southeast Asia, the Middle East, Eastern Europe, Southern Europe, and the former Soviet Union.1
  • Have long-term (chronic) liver disease.
  • Use illegal injectable drugs.
  • Have anal contact with a sex partner.
  • Work in occupations that expose them to viruses, such as some lab workers, people who provide emergency medical assistance, and day care providers.
  • Have clotting factor disorders and receive blood products.

How Well It Works

In clinical trials, 1 month after the last dose, 100% of people were immune to hepatitis A, while 99.7% were immune to hepatitis B.2 But in practice, immunity may not approach these levels. Hepatitis B vaccine usually does not provide immunity for more than 95% to 97% of people.

Immunity to the hepatitis B virus is thought to be lifelong. The hepatitis A vaccine is effective for at least 25 years in adults and 14 years in children.3

Side Effects

All medicines have side effects. But many people don't feel the side effects, or they are able to deal with them. Ask your pharmacist about the side effects of each medicine you take. Side effects are also listed in the information that comes with your medicine.

Here are some important things to think about:

  • Usually the benefits of the medicine are more important than any minor side effects.
  • Side effects may go away after you take the medicine for a while.
  • If side effects still bother you and you wonder if you should keep taking the medicine, call your doctor. He or she may be able to lower your dose or change your medicine. Do not suddenly quit taking your medicine unless your doctor tells you to.

Call911or other emergency services right away if you have:

Call your doctor if you have:

Common side effects of the Twinrix vaccine include:

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Twinrix should not be given to people who are allergic to the contents of the vaccine.

To get the best protection before travel, you need 2 doses of Twinrix before departure. But if you can get only 1 dose, consider getting just the hepatitis A vaccine instead of 1 shot of combination vaccine. It may provide better protection against hepatitis A.

Taking medicine

Medicine is one of the many tools your doctor has to treat a health problem. Taking medicine as your doctor suggests will improve your health and may prevent future problems. If you don't take your medicines properly, you may be putting your health (and perhaps your life) at risk.

There are many reasons why people have trouble taking their medicine. But in most cases, there is something you can do. For suggestions on how to work around common problems, see the topic Taking Medicines as Prescribed.

Advice for women

If you are pregnant, breast-feeding, or planning to get pregnant, do not use any medicines unless your doctor tells you to. Some medicines can harm your baby. This includes prescription and over-the-counter medicines, vitamins, herbs, and supplements. And make sure that all your doctors know that you are pregnant, breast-feeding, or planning to get pregnant.


Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.

Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.


  1. Sharapov UM (2012). Infectious diseases related to travel: Hepatitis A. The Yellow Book: CDC Health Information for International Travel 2012. New York: Oxford University Press. Also available online:

  2. Twinrix: A combination hepatitis A and B vaccine (2001). Medical Letter on Drugs and Therapeutics, 43(1110): 67-68.

  3. Centers for Disease Control and Prevention (2008). Hepatitis A FAQs for health professionals. Available online:

ByHealthwise Staff
Primary Medical ReviewerE. Gregory Thompson, MD - Internal Medicine
Specialist Medical ReviewerW. Thomas London, MD - Hepatology

Current as ofNovember 14, 2014

WebMD Medical Reference from Healthwise

Last Updated: November 14, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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