Combination Vaccine for Hepatitis A and B
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.
Why It Is Used
The vaccine can prevent infection with one series of injections rather than two series. 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 the hepatitis A virus (HAV) and the hepatitis B virus (HBV). These include people who:
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.1 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.
In trials of the vaccine, no serious side effects occurred. The most common side effects were those that occur with the individual hepatitis A and B vaccines, such as:
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.
The vaccine has not been tested in pregnant or breast-feeding women, so its safety for these women and their babies is unknown.
To be most effective before travel, two doses need to be given before departure. If only one dose can be given, consider having the individual hepatitis A vaccine instead of one shot of combination vaccine. It may provide better protection against hepatitis A.1
eMedicineHealth Medical Reference from Healthwise
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