Commonly Asked Questions

Is the hepatitis B vaccine safe?

Yes, the hepatitis B vaccine is very safe and effective. In fact, it is the first  “anti-cancer vaccine” because it can protect you from hepatitis B, which is the cause of 80% of all liver cancer in the world. It only takes 3 shots to protect yourself and those you love against hepatitis B for a lifetime.

With more than one billion doses given throughout the world, medical and scientific studies have shown the hepatitis B vaccine to be one of the safest vaccines ever made.

Can I catch hepatitis B from the vaccine?

No. You cannot get hepatitis B from the vaccine because it does not contain any live virus or blood products. The vaccine is made from a synthetic yeast product in a laboratory. The most common side effects are redness and soreness in the arm where the shot is given.

If I started the vaccine series but didn't complete my 2nd or 3rd dose on schedule, do I have to start the series over?

No, there is no need to restart the series. If the series is interrupted after the first dose, the second dose should be given as soon as possible, and the third dose at least 2 months after the second. If only the third dose is delayed, it should be given as soon as possible.

I received the vaccine years ago—am I still immune?

If it has been years since you have been vaccinated, you  may need or may request an HBV surface antibody blood test to confirm that you are still protected. A person is considered protected if they have a positive anti-HBs or HBsAb test result greater than 10 mIU/mL. Sometimes these test results are under 10 and there is concern whether these low levels will still provide protection against HBV. Anti-HBs or HBsAb test results can decrease over time, but an individual can still be protected even if the test results are less than 10.

If your test results are low, your doctor may recommend a booster shot or a repeat of the series. If you confirm you completed the vaccine series, you can get a booster dose of the vaccine. Your surface antibody level will be tested again 1 or 2 months after the booster. If the blood test result is greater than 10, then you are protected and will not require an additional booster shot in the future. (Ongoing studies show continued immunity for 30 years) If a booster shot does not result in a level greater than 10, then complete the remaining two-doses of the vaccine series and recheck the levels again after 1-2 months. Retain a copy of the titer test as proof of immunity.

Should I get the hepatitis B vaccine if I have a chronic HBV infection or have recovered from a past infection?

People who have a current infection or have recovered from a past infection receive no benefit from the HBV vaccine series, though there is no risk to receiving the vaccine series. 

Where can I get vaccinated against hepatitis B?

The United States Center for Disease Control maintains a database of locations that offer the hepatitis B vaccine. You can search for locations within the U.S. here: Vaccines are widely available in the U.S. at doctor's offices, community health centers, pharmacies, and other community locations.