Hepatitis A Vaccine for Adults

Medically Reviewed by Jennifer Robinson, MD on February 23, 2024
3 min read

The hepatitis A vaccine can prevent hepatitis A, which can be a serious (although rarely fatal) liver disease that may require hospitalization. The hepatitis A virus, present in the stool of infected people, spreads through:

  • Close personal contact, such as household or sexual contact, with an infected person
  • Contaminated water or ice
  • Contaminated raw shellfish, fruits, vegetables, or other uncooked foods

If you get hepatitis A as an adult, you are more likely to have signs and symptoms than young children who are infected. Symptoms may last less than two months and include:

The CDC recommends that adults have the hepatitis A vaccine (HAV) if you:

  • Are traveling to or working in countries where hepatitis A is common (such as countries in Central or South America, Mexico, many Asian countries, Africa, and Eastern Europe); this disease is much more common than cholera or typhoid among international travelers.
  • Will have close contact with an international adoptee from a country where hepatitis A is common
  • Are a man who has sex with men
  • Use street drugs
  • Have experienced homelessness
  • Have chronic liver disease
  • You are pregnant because it may affect the outcome of your pregnancy
  • Work with primates infected with hepatitis A or with the virus in a research lab

Also, if you work with food, you should consider getting the hepatitis A vaccine.

Do not get the hepatitis vaccine if you:

  • Have ever had a severe allergic reaction to a hepatitis A vaccine or to any vaccine component; hepatitis A vaccines contain alum and some contain 2-phenoxyethanol.
  • Are ill, unless it is a mild illness
  • Are pregnant, unless you are at greater risk for contracting hepatitis A (you are traveling to places with a higher prevalence of the disease, you engage in risky behaviors, have chronic liver disease, or you are exposed during a hep A outbreak) 

You receive the injection of the hepatitis A vaccine in the muscle of your upper arm. Start the vaccine series when you are at risk of infection and at least one month before traveling. You need two doses six to twelve months apart.

There are also combination vaccines for adults that protect against both hepatitis A and hepatitis B. However, these have a different dosing schedule. Ask your doctor for details. You might prefer this option if, for example, you are traveling to countries with high rates of both diseases.

It's good to know you cannot become infected by getting the hepatitis A vaccine. But in very rare cases, people can have a severe allergic reaction to the hepatitis A vaccine. This occurs within a few minutes to hours of getting the shot. In extremely rare cases, this reaction can be fatal. It's important to remember that the risks from the disease are much greater than the risk from the vaccine itself.

Signs of a severe reaction to the hepatitis A vaccination include:

Other minor reactions to the hepatitis A vaccine that may last one to two days may include:

  • Soreness at the site of injection
  • Headache
  • Fatigue

If you have any signs of a severe reaction:

  • Call the doctor or get to a doctor right away
  • Describe when you had the vaccine and what occurred
  • Have a health care professional report the reaction