For some people, their immune system can clear the hepatitis B virus with natural immunity. However, some individuals can build immunity to hepatitis B through vaccination.

For some people, the hepatitis B virus causes mild illness and resolves within a few weeks. For others, it is potentially life threatening and can result in lifelong health complications as it inflames and damages the liver.

The hepatitis B virus, or HBV, can cause hepatitis B infection in some people. The Centers for Disease Control and Prevention (CDC) report that 880,000 to 1.89 million people are living with HBV infection in the United States.

HBV transmits through contact with blood or other bodily fluids from people who have the virus. It can also be transmitted from birth parent to infant during labor.

There is a safe and effective hepatitis B vaccine that helps a person build immunity against HBV infection.

Learn more about hepatitis B, including what it means to have immunity and how the hepatitis B vaccine can provide immunity to some people.

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Hepatitis B is a liver infection caused by HBV. For some people, HBV infection can lead to chronic liver disease, liver failure, and even death.

Individuals can contract hepatitis B via blood, semen, and other bodily fluids from a person who has the virus. For example, this can happen during birth, through sexual contact, or by sharing needles, syringes, or other drug equipment.

People who have HBV may experience the following symptoms:

The risk of developing chronic HBV depends on the age at transmission. The CDC states that around 90% of babies with hepatitis B can develop chronic infection, while 2–6% of adults become chronically infected.

There are approved drugs for adults and children that help control the hepatitis B virus, such as antivirals. While this reduces the risk of developing more serious liver disease, there is still no complete cure.

Natural immunity

Sometimes, a person’s immune system can clear HBV infection without treatment. Experts are unsure why some people may have a natural immunity to HBV.

However, hepatitis B infection can become long term for others and lead to serious health problems, such as liver cirrhosis and cancer.

The hepatitis B vaccine is a safe and effective way of helping to prevent hepatitis B infection.

All infants, children, and adults should receive hepatitis B vaccination. People exposed to the virus may also receive the hepatitis B vaccine within 24 hours, which can prevent infection in some cases.

The vaccine can offer long-term protection against HBV.

The course for infants consists of:

  • a first dose at birth
  • a second dose before 2 months
  • a third dose at 15 months

Most healthy people do not require any further vaccinations.

If adults did not receive hepatitis B vaccination at birth, the schedule consists of two, three, or four doses depending on their health and the vaccine type.

Booster doses

The CDC does not recommend booster doses for healthy people with a normal immune status who have already received the vaccine.

Some people may receive boosters, such as those on hemodialysis whose test results show that antibodies to hepatitis B surface antigen have fallen by <10 milli-international units per milliliter.

The hepatitis B vaccine is safe and well-studied. Most people experience no adverse effects following vaccination. However, mild side effects may include:

  • tenderness at the injection site
  • redness and swelling at the injection site
  • headaches
  • fever

In some rare cases, an individual may experience a severe allergic reaction to the hepatitis B vaccine. If an individual develops any of the following signs, they should seek emergency medical treatment:

Doctors must closely monitor pregnant people who have HBV.

There is a risk that the virus can pass from parent to child during delivery without the correct treatment. Therefore, all people should receive hepatitis B testing during pregnancy. A person with chronic hepatitis B should talk with a doctor about the risks and benefits of antiviral treatment while pregnant.

According to the Hepatitis B Foundation, if someone has HBV, their newborn must immediately receive the first dose of the hepatitis B vaccine and hepatitis B immune globulin (HBIG) within 12 hours of birth. The infant should then receive the second and third doses of the vaccine according to the standard childhood immunization schedule.

Pregnant people unsure of their vaccination status can safely receive the hepatitis B vaccine during pregnancy and breastfeeding or chestfeeding.

However, there is currently not enough safety information about Heplisav-B and PreHevbrio, so pregnant people should receive Engerix-B, Recombivax HB, or Twinrix.

Doctors may order a panel of blood tests to check if someone has HBV:

  • Hepatitis B surface antigen (HBsAg): This test looks for the presence of HBV in the blood by looking for antigens found on the virus. A positive result means that a person has HBV.
  • Hepatitis B surface antibody (anti-HBs): This test can show if a person is immune and protected against HBV. A positive result indicates that the person has overcome a past HBV infection or it is the result of receiving the hepatitis B vaccine.
  • Hepatitis B core antibody (anti-HBc): This test looks for another antibody in the HBV, but this one does not provide protection. A positive result indicates that a person had a past infection or currently has HBV.

Some people with certain risk factors for hepatitis B infection, such as those who inject drugs, pregnant people, and other populations, may require testing postvaccination to check their immunity.

Some individuals may complete hepatitis B vaccination and not develop protective antibodies. Doctors refer to these people as nonresponders.

The Hepatitis B Foundation notes that up to 15% of vaccinated individuals may not respond to vaccination due to chronic illnesses, having obesity, smoking, or advancing age.

Another reason is that a person may already have had HBV. Therefore, doctors may test for the hepatitis B surface antigen or HBsAg before deciding they are a vaccine nonresponder.

If someone does not respond to the primary hepatitis B vaccine series, they should complete a second series with a different brand of vaccine. Doctors may also recommend a 2-dose vaccine schedule if someone does not respond to the initial hepatitis B vaccine schedule.

Doctors should check anyone revaccinated around 1–2 months following the last dose of the schedule to determine if their antibodies have responded.

The World Health Organization (WHO) recommends that all babies receive the hepatitis B vaccine to protect them against HBV infection.

Other ways to prevent transmission of the virus can include:

  • using barrier contraception during sex
  • limiting sexual partners
  • avoiding sharing needles or personal items such as toothbrushes and razors

Hepatitis B is an infection caused by the hepatitis B virus. For some people, it can cause serious liver damage, cirrhosis, and cancer if left untreated. People can contract HBV infection through contact with bodily fluids from someone who has the virus.

There is a safe and effective hepatitis B vaccine that most people receive at birth. However, should someone acquire chronic HBV, doctors may treat it with antiviral medications or other drugs to boost the immune system, though there is no complete cure.