Hepatitis B vaccines are usually administered in a three-dose series over a period of 6 months for both children and adults. However, this may vary for different types of vaccines.

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The hepatitis B virus (HBV) is spread through blood and other bodily fluids and can cause a liver infection. There are two types.

Acute HBV lasts for a short amount of time, and people often make a full recovery. In some cases, it can progress to a chronic condition. Chronic HBV can be managed but not cured, and can result in serious complications. It’s estimated that around 800,000 people in the United States live with chronic hepatitis B.

The hepatitis B vaccine can protect you from contracting the virus that causes hepatitis B infections. HBV vaccines have been safely used since the early 1980s. As of 2020, the World Health Organization estimates that the vaccine for hepatitis B is between 98 and 100 percent effective.

Virologists have developed recommendations for vaccinations to protect against hepatitis B. The schedule is based on the type of vaccine you will receive.

In children

The recommendations for hepatitis B vaccine for children are:

  • First dose: within 24 hours of birth
  • Second dose: 1-2 months of age
  • Third dose: 6-18 months of age

In adults

Adults who were not vaccinated as children can also pursue a three-dose schedule:

  • First dose: as soon as you are able
  • Second dose: 1 month after the first dose
  • Third dose: 6 months after the first dose

There are certain brands of vaccines that follow a different schedule.

What to do if you miss a scheduled dose

The recommended schedule for the HBV vaccine follows a three-dose pattern, with all doses complete within 6 months. The good news is that if you miss a dose, you don’t need to start the series of shots all over.

If you missed getting the second dose 1 month after the first, make an appointment as soon as possible. If you miss the third dose, you should also try to get it as quickly as possible. Keep in mind that the second and third doses should be separated by at least 8 weeks.

For children

The brand names for the three-dose hepatitis B vaccines most commonly used in the United States are:

  • Engerix-B (made by GlaxoSmithKline)
  • Recombivax HB (made by Merck)
  • Pediarix (a combination vaccine that includes DTaP and inactivated poliovirus; usually given in four doses)

For adults

In addition to Engerix-B and Recombivax HB, there’s another HBV vaccine approved for adults in the United States. This vaccine is called HEPLISAV-B.

This formula is newer but it’s believed to be just as effective. It requires two doses instead of three, and the second dose can be administered 4 weeks after the first. HEPLISAV-B is currently not recommended for pregnant women.

There’s also the option to get vaccinated for hepatitis B and hepatitis A at the same time. Twinrix (made by GlaxoSmithKline) can be given in three or four doses. Twinrix typically follows the same schedule as the other HBV vaccines, but it can also follow an accelerated schedule, which is three doses in the span of a month followed by a booster shot 12 months later.

Adults who were vaccinated as children, and people who are pregnant, are currently not recommended to get a booster shot, according to the CDC. Studies indicate that if you were vaccinated as a child, you are most likely protected against HBV for a minimum of 30 years, and most likely for much longer.

As stated above, adults who get the Twinrix vaccine on an accelerated schedule will need a booster shot after 12 months.

People who are on dialysis may be advised by their healthcare provider to get a booster shot. People with an ongoing risk of HBV exposure, who have taken a blood test that shows their immunity to the virus has weakened, may also be advised to get a booster. In general, most people won’t need to get a HBV booster during their lifetime.

Hepatitis B is a viral infection that can’t be transferred person-to-person unless you have contact with an infected person’s bodily fluids. Annual infection rates of HBV are going down in the United States thanks to vaccines. So you might be wondering if you or your child needs a shot to protect against hepatitis B.

Hepatitis B can cause serious health complications

Most adults with acute HBV make a full recovery after getting the virus that causes it. However, not everybody does. The CDC reported that 1,649 people died in 2018 of complications caused by hepatitis B. Cirrhosis (liver scarring), liver disease, and liver cancer can result from contracting HBV.

Babies and children can develop chronic HBV

You may be wondering why the recommendations for the HBV vaccine start on the first day of life.

Adults who contract HBV will likely not experience long-term complications from hepatitis B. But the same is not the case for babies. As many as 90 percent of babies who contract an HBV infection at birth from their mothers become chronically infected with HBV.

Children between the ages of 1 and 5 who get an HBV infection have a 30 to 50 percent risk of a chronic infection. About 25 percent of people who become chronically infected during childhood will develop liver cancer or cirrhosis. That’s why pediatricians want children to have immunity from HBV from the earliest possible age. Many babies and children exposed to HBV (including at birth) receive post-exposure prophylaxis, which decreases chance of infection.

If you’re pregnant, you’ll most likely have a blood test to see if you’re positive for hepatitis B. This allows doctors to find out if there’s a chance that you could pass on the virus. These tests are highly sensitive and have a good accuracy rate, but they aren’t perfect. Additionally, a pregnant person may become infected between the time of the test and giving birth. The first dose of the vaccine given at birth lowers the risk of a newborn baby contracting hepatitis B.

Many people with HBV don’t know they have it

HBV infections are becoming less common in the United States. But HBV is still widespread in other parts of the world. Around 257 million people living around the world currently have HBV, and many of them don’t know it. Chronic HBV is often asymptomatic, and even when it isn’t, it can take months for symptoms to show up.

HBV can be transmitted through sexual contact and the use of IV drugs (transmission is more likely in areas with higher rates of HBV infections), and other risk factors. Although rare, there have been cases where people have acquired HBV through emergency blood transfusions.

There are potential side effects for adults and children in the days following a dose of the HBV vaccine.

Common side effects include:

  • pain, swelling, or redness at the injection site
  • fever
  • headache
  • runny nose or nasal congestion

Severe side effects from the hepatitis B vaccines are rare, but have been reported. Seek emergency medical assistance if you notice any of the following after a dose of HBV vaccine:

  • hives
  • difficulty breathing
  • dizziness
  • muscle weakness
  • swelling of your face or throat

Who shouldn’t get the hepatitis B vaccine?

Some people should not get the hepatitis B vaccine. If you’ve had a serious allergic reaction to a hepatitis B vaccine in the past, you should not get additional doses. All HBV vaccines approved for use in the United States currently contain yeast, so if you have a yeast allergy, talk with a doctor if considering the vaccine. People who are allergic to the antibiotic neomycin should avoid the Twinrix shot.

Information about vaccine formula ingredients is available online.

The schedule for the hepatitis B vaccine is based on which type of vaccine you receive. Most HBV vaccines for children and adults are administered in a three-dose series over the course of 6 months.

Vaccination for hepatitis B is currently recommended for all babies, starting at birth, but certain people at higher risk of HBV infection should make sure they have been fully vaccinated.

The HBV vaccine can cause side effects. Speak to a doctor if you have any questions or concerns about these vaccines or your risk for HBV.