Why You Need the Hepatitis A Vaccine

The hepatitis A vaccine can prevent you from developing hepatitis A, an infection that affects about 1.4 million people worldwide every year.

Hand washing and a clean water supply are measures that can help reduce the spread of this disease, but vaccination can prevent it even if you are unintentionally exposed.

Close-up of a needle and medicine vial
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What Is the Hepatitis A Vaccine?

Hepatitis A vaccine is a safe and effective preparation containing inactivated hepatitis A viruses.

Your body can't tell difference between inactive viruses and live viruses—so your immune system will start producing antibodies against the inactivated viruses. The vaccine generates an immune response without exposure to the live, harmful form of the virus.

Your vaccine-mediated immunity should last for years, and your immune system will be ready in case you are exposed to the hepatitis A virus in the future. This immunity helps you fight off the virus quickly, before the infection has a chance to make you sick.

There are two very similar hepatitis A vaccines available in the United States:


Both are available for anyone one year of age or older and require two doses—the second dose should be scheduled between six to 18 months after the first.

Another vaccine, TWINRIX, is a combination vaccine that protects against hepatitis A and hepatitis B. It requires three or four doses and is only approved for people 18 years of age and older. All hepatitis A vaccines offer immunity that will last up to 20 years.

Should You Be Vaccinated?

Most people will benefit from being vaccinated. However, anyone who is at increased risk of hepatitis A infection is strongly encouraged to be vaccinated.

According to the Centers for Disease Control and Prevention (CDC), the vaccine is recommended for:

  • All children 12-23 months old, and all older children 2-18 yrs old who have not previously been vaccinated
  • People who travel to a country that has a high rate of hepatitis A infection
  • Men who have sexual contact with other men
  • People who use illegal drugs
  • People who have chronic liver disease, including hepatitis B or hepatitis C
  • People with occupational risk to exposure (such as working with animals or in a laboratory)
  • People who are HIV positive
  • People who anticipate close personal contact with an international adoptee
  • People experiencing homelessness
  • Anyone who would like to become immune

Some people should not be vaccinated for hepatitis A. These include infants who are younger than one year old and anyone who has ever had a serious allergic reaction to the hepatitis A vaccine.

Also, although it's safe, the hepatitis A vaccine is not necessary if you've ever had hepatitis A infection—you should have developed immunity due to the infection. However, you need to be certain you've had hepatitis A before you decide that you don't need the vaccine. Sometimes people confuse one type of viral hepatitis with another or misunderstand a test result they once received. You should talk with your doctor to be certain.

Is This Vaccine Safe?

The hepatitis A vaccine is considered to be very safe and has been given millions of times. The most common side effect is soreness around the area of the injection. Serious side effects are extremely uncommon.

Because it contains inactivated viruses, hepatitis A vaccine can't cause an infection and is considered safe for pregnant women and people who have compromised immune systems (for example, someone infected with HIV).

People who worry that vaccines cause other health problems, such as autism or mercury exposure, should know that hepatitis A vaccine hasn't been linked to any medical problems other than rare allergic reactions.​

What Is IG?

Immune globulin, also called IG, is a type of immunization therapy that uses antibodies instead of viruses. This type of immunity is called passive immunity because it offers protection without your body having to do anything.

If you've already had a known exposure or high-risk travel, the best protection might be for you to receive immune globulin. Depending on the circumstances, your doctor might recommend that you receive immune globulin or the first dose of the hepatitis A vaccine, or both.

Where Can You Be Vaccinated?

You should talk to your primary care doctor about getting vaccinated for hepatitis A. City or county health departments usually offer vaccination clinics that may be free or require only a small charge.

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Article Sources
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  1. World Health Organization. Hepatitis A. Updated October 19, 2015.

  2. Centers of Disease Control and Prevention. Hepatitis A Questions and Answers for Health Professionals. Updated September 10, 2019.

  3. Centers for Disease Control and Prevention. Hepatitis A Questions and Answers for the Public. Updated September 10, 2019.