What Is Hepatitis B?

Hepatitis B is a disease caused by the hepatitis B virus (HBV). This virus attacks the liver. The disease can cause:

HBV is spread through the blood of an infected person.

It is estimated that 1 in 20 people in the US will get infected with HBV sometime during their life. Certain factors increase the risk of developing hepatitis B, including:

  • Having sex with someone infected with HBV
  • Having multiple sexual partners
  • Injecting illegal drugs
  • Having male homosexual sex
  • Living in the same house as someone with chronic hepatitis B
  • Coming in contact with human blood
  • Working in the home of someone who is developmentally disabled
  • Having hemophilia
  • Traveling to areas where hepatitis B is common
  • Having parents born in Southeast Asia, Africa, the Amazon Basin in South America, the Pacific Islands, or the Middle East

About 30% of people with hepatitis B will not have symptoms. For people who do, symptoms may include:

  • Yellowing of the skin and eyes (jaundice)
  • Fatigue that lasts for weeks or even months
  • Abdominal pain in the area of the liver (upper right side)
  • Loss of appetite
  • Nausea
  • Vomiting
  • Joint pain
  • Low-grade fever
  • Dark urine and light-colored stool
  • Widespread itching
  • Rash

Symptoms generally occur about 12 weeks after exposure. They can occur anywhere from 9-21 weeks after exposure. Most hepatitis B infections clear up within 1-2 months without treatment. But when an infection lasts more than six months, it can develop into chronic hepatitis B. This can lead to serious complications, even death.

Chronic hepatitis B can be treated with antiviral drugs.

What Is the Hepatitis B Vaccine?

The hepatitis B vaccine is produced by inserting a gene for HBV into yeast. The yeast is grown, harvested, and purified. The vaccine is given as an injection into the muscle.

Who Should Get Vaccinated and When?

Everyone age 18 and younger and adults over the age of 18 who are at risk should get the vaccine. Adults who are at risk include:

  • People who have had more than one sexual partner in six months
  • Men who have sex with other men
  • Sexual partners of infected people
  • People who inject illegal drugs
  • Healthcare and public safety workers who might be exposed to HBV-infected blood or body fluids
  • Those living with people with chronic HBV infection
  • Hemodialysis patients

Three doses are given. Newborns receive the first dose before leaving the hospital. If the mother is infected with the virus, the dose is given within 12 hours of birth. The second dose, for all infants, is given at 1-2 months of age, and the third dose at 6 months of age.

Children and adults who have not been previously vaccinated should have an interval of at least 1 month between the first and second dose. The third dose should be given at least 2 months after the second. For children aged 11-15 years, there is a 2-dose series available, called Recombivax HB.

What Are the Risks Associated With the Hepatitis B Vaccine?

All vaccines are capable of causing serious problems, such as a severe allergic reaction.

Most people who get the hepatitis B vaccine do not have problems. Some may have mild problems, including soreness where the shot was given and fever.

Acetaminophen (eg, Tylenol) is sometimes given to reduce pain and fever that may occur after getting a vaccine. In infants, the medicine may weaken the vaccine's effectiveness. Discuss the risks and benefits of taking acetaminophen with the doctor.

Who Should Not Get Vaccinated?

You should not get the vaccine if you:

  • Had a life-threatening allergic reaction to baker's yeast or to a previous dose of hepatitis B vaccine
  • Are moderately or severely ill—Wait until you recover to get the vaccine.

What Other Ways Can Hepatitis B Be Prevented Besides Vaccination?

Other than getting the hepatitis B vaccine, the best methods of preventing an HBV infection include:

  • Practicing safe sex
  • Getting a blood test for hepatitis B if you are pregnant
  • Avoiding illegal drugs
  • Not using other people's personal care items that may have blood on them (eg, razors, toothbrushes)
  • Considering the risks before getting a tattoo or body piercing
  • Following safety precautions when handling needles or other sharp objects

What Happens in the Event of an Outbreak?

In the event of an outbreak, all susceptible people should be offered the vaccine.