Although it is unclear exactly how long the hepatitis A vaccine works, it does provide long-term protection. In fact, it may offer lifelong protection against the hepatitis A virus.

The hepatitis A vaccine is an inactivated vaccine. This means it contains the killed version of the hepatitis A virus.

This article looks at the best candidates for the hepatitis A vaccine and when to get vaccinated.

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According to the Centers for Disease Control and Prevention (CDC), it is unclear precisely how long protection lasts after getting the hepatitis A vaccine.

The CDC notes that research suggests protection against the hepatitis A virus (HAV) may last at least 20 years in people who receive the full vaccine series.

The nonprofit Immunize.org suggests that the hepatitis A vaccine might last at least 25 years for adults and about 14–20 years for children.

A 2020 review of research states that two doses of the hepatitis A vaccine may protect for 30–40 years or provide lifetime protection.

Experts are continuing to research the long-term effectiveness of the hepatitis A vaccine.

According to the U.S. Department of Health and Human Services (HHS), every child requires a hepatitis A vaccine.

Children need two doses of the vaccine as part of their routine vaccinations. The first dose should be administered at 12–23 months old and the second dose at 2–4 years old.

Adults with an increased risk of HAV infection may also need the vaccine. This includes:

  • people traveling internationally
  • males who have sex with males
  • people who use drugs with or without needles
  • people at risk of exposure due to their occupation
  • people who may have close personal contact with an international adoptee
  • people without housing

Other recommendations for people to receive the hepatitis A vaccine include:

  • people at increased risk of severe disease from HAV infection, which includes people living with chronic liver disease or HIV
  • any person who is pregnant and at risk of HAV infection or severe disease from HAV infection
  • those who are unvaccinated in an outbreak area who have a risk of HAV infection or severe disease from HAV infection

The vaccine is also available to anybody who requests it.

The vaccine is not suitable for people who have ever had a severe allergic reaction to the hepatitis A vaccine or if they are allergic to any component of the vaccine.

People need to tell a doctor if they are ill before they receive the vaccine, as they may need to wait before getting it.

There are currently two brands of hepatitis A vaccine available in the United States: Havrix and Vaqta.

The vaccine schedule varies slightly depending on which vaccine people receive. There is no evidence suggesting any significant differences between either vaccine.

Children can receive their first vaccine at 12 months old or older. According to Immunize.org, the second dose of the hepatitis A vaccine must be 6–12 months apart for the Havrix vaccine and 6–18 months apart for the Vaqta vaccine.

Adults also need two doses of the vaccine, with the second dose 6–12 months after the first dose if they receive the Havrix vaccine and 6–18 months after the first dose for the Vaqta vaccine.

Before travel

If people have previously received the two-dose vaccination schedule, they do not require a hepatitis A booster or any other hepatitis A vaccine before traveling.

If people have not received hepatitis A vaccination, they need to receive the first dose as soon as they know they will be traveling, and then receive the second dose as per the vaccination schedule.

If infants 6–11 months old are traveling outside the United States and require protection against HAV infection, they can receive one travel dose. This does not form part of the routine hepatitis A vaccination schedule, which they need to begin in full from the age of 1 year onward.

People may be able to get the hepatitis A vaccination at a pharmacy, doctor’s office, travel clinic, or health center. The vaccine may be free or low cost. Alternatively, a person’s insurance may cover it.

People can find out further information using the HHS website.

The following are commonly asked questions about the hepatitis A vaccine.

How is the hepatitis A vaccine made?

The hepatitis A vaccine uses cell culture to make the vaccine. This includes taking cells of the hepatitis A virus and growing them in cells from humans called fibroblasts.

Scientists then use the chemical formalin to inactivate the virus and combine it with an aluminum hydroxide adjuvant. This substance helps the immune system respond to a foreign substance.

What are the side effects of the hepatitis A vaccine?

If people experience side effects of the hepatitis A vaccine, they are usually mild and temporary.

Side effects may include soreness at the injection site, tiredness, headache, and fever.

These side effects typically resolve within a few days. Serious side effects of the vaccine are rare.

The most commonly reported side effects of the hepatitis A vaccine include reaction at the injection site, rash, and fever.

What level of protection does the hepatitis A vaccine offer?

According to the CDC, the hepatitis A vaccines are highly effective at preventing HAV infection. Completing the full vaccination schedule offers long-term protection against the virus.

According to Immunize.org, the vaccination likely offers immunity against hepatitis A in anyone who receives two doses. At least 94 out of 100 people who receive one dose have immunity for several years.

The hepatitis A vaccine provides long-term protection against the hepatitis A virus (HAV). The vaccination schedule includes two doses. It is available for adults and children over 12 months old.

People can talk with a doctor, pharmacy, or travel clinic about getting the vaccine.