Treating Hepatitis A With Immune Globulin

Hepatitis A immune globulin (IG) contains antibodies that protect your body from hepatitis A. It's similar to the hepatitis A vaccine in that it can prevent the disease from developing, but it works very differently.

IG can treat a person recently exposed to hepatitis A so that the virus will only cause a mild infection, or at best, prevent the disease completely. IG can also be used to prevent infection.

IG Before a Possible Hepatitis A Exposure

If you haven't had time to get the Hepatitis A vaccine, and plan to travel to a country where hepatitis A is epidemic or a place where there's a hepatitis A outbreak, you can take IG for temporary protection. This is called pre-exposure immunoprophylaxis.

However, since IG will only give you about 3 months of protection, a better strategy is to use both IG and the hepatitis A vaccine. In people with no medical problems who are between 1 year and 40 years old, a single dose of the hepatitis A vaccine anytime before departure is adequate.

But for the following group of people, you should have the first HAV vaccine and the IG injection: those who are older than 40, those with weak immune system, those with advanced liver disease or another serious chronic condition.

You should receive this double-protection method if you are departing within two weeks of your doctor's visit. The second part of the vaccine must be given to you upon your return from your trip for long-term protection. This combination will give you the immediate protection that lasts for about 20 years.

The recommended dose for pre-exposure is 0.02 mL of IG for every kilogram of body weight. This means that a person who weighs 100 pounds needs about 0.9 mL of IG. For longer trips, a higher dose may be necessary.

IG After a Hepatitis A Exposure

If you know you've been exposed to hepatitis A, you can help protect yourself by taking either IG or hepatitis A vaccine. This therapy is called postexposure immunoprophylaxis and can help lessen the infection or even prevent infection completely. Your age determines if you should take vaccine or IG.

• Children who are less than one year old should use IG.
• People older than 12 months, but are 40 years old or younger (and do not have any chronic medical conditions) should receive the hepatitis A vaccine instead of IG.
• People who are 41 years old or greater, IG is preferred.
• People who have compromised immune systems (due to an organ transplant or diseases such as cancer or AIDS) or chronic liver disease or are allergic to the vaccine should use IG.

It's very important to take IG within two weeks of any exposure to hepatitis A. If taken during this period, IG can prevent symptoms developing 85% of the time. The recommended postexposure immunoprophylaxis for IG is 0.02 mL of IG for every kilogram of body weight. This means that a person who weighs 100 pounds needs about 0.9 mL of IG. There are many situations where you can be exposed to Hepatitis A, such as:

• Living with someone who has hepatitis A
• Having sex with someone who has hepatitis A
• Sharing illegal drugs with someone who has hepatitis A
• Working in a child-care center involving confirmed hepatitis A cases
• Being exposed to hepatitis A through a food handler

Is IG for Hepatitis A Safe?

Yes, IG for hepatitis A is very safe. The most common side-effects are pain and discomfort at the site of the injection, low-grade fever, headache, chills, and nausea. Serious complications are very rare but can include chest pain, difficulty breathing, and anaphylaxis. IG is completely safe for women who are pregnant or breastfeeding.