This is a vaccine against Hepatitis A infection.

This vaccine aims to prevent Hepatitis A infection, a liver infection that occurred in approximately 40,000 people in the United States in 2005. The vaccine will not protect against other forms of hepatitis. It is recommended for children 12 months to 18 years old, for anyone at increased risk for Hepatitis A infection, and for anyone who desires protection from Hepatitis A. You do not need this vaccine if you have already had Hepatitis A disease.

The deltoid muscle is the preferred site for injecting this vaccine.

People with immune problems are sometimes given the vaccine, since it is inactivated, but they may not mount a complete response. Side effects are not common but can include pain, swelling, warmth, and or redness at the injection site. Less commonly, other reactions can occur including rash and fever in 1-2 year olds; headache, sore throat or abdominal pain in older children and teens; and fatigue, fever, abdominal pain, headache, sore throat, and diarrhea in adults. Rare instances of severe reactions including Guillain-Barré have been reported. Safety in pregnancy or nursing mothers has not been established.

Most people have immunity to the Hepatitis A virus a month after the first shot, but protection is virtually 100% one month after the second shot. Post-vaccination testing for immunity is not recommended since the vaccine is so effective and testing is not always accurate.

Individuals with prior severe reactions to this vaccine may not be able to receive another dose. Check with your doctor regarding this issue and for any other contraindications for this vaccine. Also check with your doctor to find out what other ingredients may be in the vaccine, its container, or any diluent in case of allergies or other concerns. Immunization is usually postponed for individuals with a moderate or severe acute illness.

This immunization is recommended for all children ages 12 months-23 months to all individuals with risk factors, or to anyone who desires immunity. A second or "booster" shot is given 6-18 months after the first shot (Vaqta® 6-18 months; Havrix® 6-12 months).

Adults have the option of getting a combined Hepatitis A and B vaccine (Twinrix®-GlaxoSmithKline), given in 3 doses with the second dose given 1 month after the first dose, and the third dose given 6 months after the first dose. Alternatively, adults can have a 4-injection Twinrix® series at 0 days, 7 days, 21-30 days, and 12 months. Risk factors for Hepatitis A include: household and sexual contacts of infected people, men who have sex with men, drug users (intravenous and non-intravenous), chronic liver disease, people who receive clotting factor concentrates, some people working in child day-care centers or caring for institutionalized patients (data varies, maybe only if outbreak known), people working with the virus or with non-human primates, military personnel, people living in or travelling to areas with high infection rates some of which include Africa, Asia (not Japan), and the Middle-East. Individuals who will be in close contact (within 60 days of arrival in the U.S.) with adoptees from countries with significant amounts of hepatitis A infection should be immunized and should receive the first dose at least two weeks before contact.

• Travelers, including military personnel, to areas of substantial risk of Hepatitis A
• Men having sex with men
• Close (including sexual) contacts of infected persons
• Users of illegal drugs including non-injectable drugs
• People who receive clotting factor concentrates
• People working with the virus or with non-human primates
• People with chronic liver disease (at increased risk for liver failure if they get Hepatitis A)

Available brands of this vaccine include:

• Vaqta®
• Havrix®
• Twinrix® (combined with Hepatitis B vaccine; for ages 18 and older)