Hepatitis B is a liver infection that spreads through blood and body fluids, and it can become a lifelong illness. The good news is that a safe, widely used vaccine prevents it. This guide explains who should get the hepatitis B vaccine, how many shots are needed, how long protection lasts, and where to get vaccinated. It also covers who may need a slightly different plan. The information here is general and does not replace advice from your own healthcare provider.
Key Takeaways
- Hepatitis B spreads through blood, semen, and other body fluids, not casual contact.
- Vaccination is recommended for all infants, children, teens, and adults through age 59.
- Most people need a series of two or three shots to be fully protected.
- Protection lasts for decades, and most healthy adults do not need a booster.
- The vaccine is considered safe during pregnancy and for most people with health conditions.
What the hepatitis B vaccine does
Hepatitis B is caused by a virus that infects the liver. Some people clear it on their own, but others carry it for life, which can lead to liver damage, cirrhosis, or liver cancer. The vaccine teaches your immune system to recognize and fight the virus before you are exposed. It contains no live virus, so it cannot give you hepatitis B. When the full series is completed, the vaccine prevents infection in most people. It also protects others, because fewer people means fewer chances for the virus to spread. The vaccine is not a treatment. If you already have hepatitis B, the vaccine will not clear it, so a provider can discuss testing and care. Learn more about hepatitis and STDs and how these infections spread.
Who should get the hepatitis B vaccine
- All infants, ideally within 24 hours of birth
- All children and teens under 19 who were not vaccinated
- All adults ages 19 through 59, whether or not they have risk factors
- Adults 60 and older who have risk factors, and any adult 60+ who wants protection
- People with jobs or health conditions that raise their risk, such as healthcare work, dialysis, diabetes, or HIV
How many shots you need and when
Most people need a series of shots rather than a single one. Depending on the product used, the series is either two shots given about a month apart or three shots given over roughly six months. Your provider will tell you which schedule fits you. Finishing the series matters more than perfect timing. If you miss a shot, you usually do not have to start over. In most cases you simply continue from where you left off. If you are not sure whether you completed the series, a blood test can check your immunity, and a provider can advise whether you need more shots. Tell your provider if you need protection quickly, for example before travel or starting a new job. The vaccine can often be given at the same visit as other vaccines.
How well it works and how long protection lasts
Protection is strong. When the full series is completed, the vaccine prevents hepatitis B in roughly 9 out of 10 healthy adults and in an even higher share of infants and young children. Protection lasts for decades. For most healthy people who finished the series, no booster is recommended later in life. Certain groups, such as people on dialysis or with weakened immune systems, may need periodic testing or extra shots. If you were vaccinated long ago and are not sure it worked, a blood test can measure your antibody level. Even when you are protected against hepatitis B, other infections may still be a concern. See how often to get tested to plan a routine that fits your situation.
Who may need a different plan
| Group or situation | What the guidance says |
|---|---|
| Adults 60 and older without risk factors | Vaccination is not routinely required, but you may still choose to get it. |
| Pregnant people | The vaccine is considered safe in pregnancy and is recommended for those at risk. Talk with your prenatal provider. |
| People on dialysis or with weakened immune systems | Extra shots or periodic antibody testing may be recommended. |
| People who already have hepatitis B | The vaccine will not treat an existing infection. Regular monitoring and care are needed instead. |
| People who missed one or more shots | Continue the series where you left off. Starting over is usually not necessary. |
Where to get it, cost, and safety
You can get the hepatitis B vaccine at a doctor's office, a pharmacy, a community health clinic, or your local health department. Many insurance plans cover it as preventive care with no copay, and programs exist for people without insurance. See free and low-cost testing options for places that offer sexual health services at little or no cost. Side effects are usually mild and short lived. The most common one is a sore arm where the shot went in. Some people feel tired or get a mild fever for a day or two. Serious allergic reactions are rare. The vaccine is considered safe for most people, including pregnant people and those with weakened immune systems. Tell your provider about any past reaction to a vaccine or a serious allergy. Decisions about vaccination and your sexual health should be made with a qualified healthcare provider.
Frequently Asked Questions
Who should get the hepatitis B vaccine?
The CDC recommends it for all infants at birth, all children and teens under 19, and all adults ages 19 through 59. Adults 60 and older can also get it, especially if they have risk factors.
How many doses of hepatitis B vaccine do I need?
Depending on the product used, the series is either two shots about a month apart or three shots given over about six months. Completing the full series is what gives you protection.
How long does hepatitis B vaccine protection last?
For most healthy people who finish the series, protection lasts for decades and no booster is needed. People with weakened immune systems may need periodic testing or extra shots.
Can I get the hepatitis B vaccine while pregnant?
Yes. The vaccine is considered safe during pregnancy and is recommended for pregnant people who are at risk. Ask your prenatal provider about the best timing for you.