Skip to content

Children's Vaccines Health Center

Font Size

Hepatitis A and B Vaccines


What Is Hepatitis B and How Does It Differ From Hepatitis A? continued...

Unlike hepatitis A, hepatitis B is not spread through food or water, and you can't get it from sharing eating utensils, hugging, kissing, holding hands, coughing, or sneezing. And if you are an infected mother, you can't pass it on to your child through breastfeeding.

Children younger than age 6 who have hepatitis B often have no symptoms. In older children and adults, symptoms of acute hepatitis B include:

  • Fever
  • Fatigue
  • Loss of appetite
  • Nausea
  • Vomiting
  • Abdominal pain
  • Dark urine
  • Clay-colored bowel movements
  • Joint pain
  • Jaundice

Close to 90% of infants who become infected with HBV will develop chronic hepatitis B and carry the disease with them for life.

How Effective Are the Vaccines for Hepatitis A and Hepatitis B, and Are They Safe?

Both the vaccines for hepatitis A and the vaccines for hepatitis B are highly effective. In studies of the four vaccines used for hepatitis A, nearly 100% of all adults who receive one develop protective levels of antibodies within one month of receiving a single dose. In addition, eight years after receiving two or more doses, 99% to 100% of vaccinated individuals were still fully protected. Results are similar for the hepatitis B vaccine, and experts estimate that both vaccines will give immunity for up to 20 or 30 years and possibly for life.

As with all medications, there is the potential for side effects. But the safety record of both vaccines is outstanding. The most common side effect of the hepatitis B vaccine is soreness at the site of the injection. Since 1982, when the hepatitis B vaccine became available in the U.S., more than 100 million people have been vaccinated with no report of serious side effect. In that same time period, the incidence of acute hepatitis B declined by about 82%.

Mild side effects for the hepatitis A vaccine include soreness at the injection site, headache, loss of appetite, and tiredness. Serious side effects include a severe allergic reaction within a few minutes to a few hours of receiving the shot, but such occurrences are extremely rare.

Who Should Get the Hepatitis A Vaccine?

The CDC recommends that all children between ages 12 months and 23 months be vaccinated with the hepatitis A vaccine. No vaccine for hepatitis A is licensed in the U.S. for children under the age of 1. In addition, the following people are considered at risk for hepatitis A and should be vaccinated:

  • People ages 1 year and older who are traveling to or working in countries with a high or intermediate incidence of hepatitis A
  • Children and adolescents through age 18 who live in states or communities that have implemented routine vaccination because of a high rate of disease
  • Men who have sex with men
  • Anyone who uses street drugs
  • Anyone with chronic liver disease
  • Anyone treated with clotting factor concentrates, such as people with hemophilia
  • Anyone who works with HAV-infected primates or in HAV research laboratories

You should not get the vaccine if you have ever had a severe allergic reaction to an earlier dose of the vaccine. You should also tell your doctor about any allergies you have and not get vaccinated if you are allergic to any component to the vaccine. Also, the safety of the vaccine for pregnant women is not known, although the risk is considered to be very low.

Next Article:

Today on WebMD

Baby getting vaccinated
Is there a link? Get the facts.
syringes and graph illustration
Get a customized vaccine schedule.
baby getting a vaccine
Know the benefits and the risk
nurse holding syringe in front of girl
Should your child have it?

What To Know About The HPV Vaccine
24 Kid Illnesses Parents Should Know
Nausea and Vomiting Remedies Slideshow
Managing Immunization Schedules For Kids

Doctor administering vaccine to toddler
gloved hand holding syringe
infant receiving injection

WebMD Special Sections