What is hepatitis B?

Hepatitis B is a highly contagious liver infection caused by the hepatitis B virus (HBV). The infection can range in severity from mild to acute. It may last just a few weeks or become a serious, chronic, and potentially fatal health condition.

The best way to prevent this infection is to get the hepatitis B vaccine. Here’s what you need to know.

The hepatitis B vaccine is used to prevent hepatitis B. It’s usually provided in three doses.

The first dose can be taken on a date you choose. The second dose must be taken 1 month later. The third and final dose must be taken 6 months after the first dose.

Some people may need two or four doses of this vaccine.

There is also a newer hepatitis B vaccine that’s offered in two doses.

Who should get the HBV vaccine?

The Centers for Disease Control and Prevention (CDC) recommends that all children and adults up to age 59 should receive the hepatitis B vaccine.

Infants should get their first hepatitis B vaccine within 24 hours of birth and complete their doses by age 6 to 18 months.

All unvaccinated children and adults through age 59 should receive the vaccine. Also, unvaccinated adults over the age 60 who are at risk of hepatitis B should get the vaccine.

Adults over age 60 who are not at risk of hepatitis B may also choose to get the shot.

Several types of the HBV vaccine are also safe to administer to pregnant women.

Risk factors for hepatitis B include:

  • people who have had more than one sex partner in the last 6 months
  • men who have sex with men
  • people seeking treatment for a sexually transmitted infection
  • people whose partners or household members have hepatitis B
  • people who inject drugs
  • people who live or work in care facilities
  • people who are on dialysis
  • travelers to countries where hepatitis B is common
  • people with chronic liver disease, HIV, or hepatitis C
  • people who are in jail or prison

People who have diabetes should talk with a healthcare professional about their risk for contracting hepatitis B.

Who should not get the hepatitis B vaccine?

Hepatitis B is a safe vaccine that does not contain a live virus.

However, there are some circumstances in which doctors advise against getting the HBV vaccine.

You should not receive the hepatitis B vaccine if:

  • you’ve had a serious allergic reaction to a previous dose of the hepatitis B vaccine
  • you have a history of hypersensitivity to yeast or any other HBV vaccine components

How effective is the vaccine?

Research from 2016 showed that the HBV vaccine results in long-term defense against the virus. Studies indicated protection for at least 30 years among healthy vaccinated individuals who started the hepatitis B vaccination before they were 6 months old.

Another 2021 study that involved surveying the health records of more than 64,000 Americans found that the vaccine effectively immunized people against hepatitis B and reduced cancer-related deaths.

The hepatitis B vaccine is considered a very safe and effective vaccine. It’s made with an inactivated (dead) virus, so most types of the vaccine are even safe for pregnant people.

The hepatitis B vaccine may cause some mild side effects. The most common symptom is redness, swelling, or soreness where the injection was given. Some people also experience headache or fever. These effects usually last a day or two.

Rarely, some people have a serious and potentially life threatening allergic reaction to the vaccine. Call 911 or get to a hospital immediately if you experience any of the following symptoms after vaccination:

  • hives
  • swelling in your face and throat
  • dizziness
  • weakness
  • difficulty breathing
  • rapid heartbeat

The hepatitis B vaccine is extremely safe. As with any medication, there is a small risk of serious issues after vaccination.

Vaccination is critical for preventing this potentially deadly infection.

The CDC estimates that more than 800,000 Americans are living with chronic hepatitis B, with over 21,000 new diagnoses occurring in 2018.

Many people don’t even know they’ve contracted HBV. Up to 40 percent of people with an untreated chronic HBV infection will develop liver cancer, according to the Hepatitis B Foundation. Thousands of deaths are linked to the virus every year.

The hepatitis B vaccine provides at least 98 percent protection to infants, children, and adults who are fully immunized before being exposed to the virus, according the World Health Organization.

The HBV vaccine is safe and helps prevent infection with hepatitis B, which reduces your risk of liver disease and liver cancer. Although some people rarely experience serious side effects, it’s most likely that you’ll have few — if any — side effects.