How is the hepatitis B vaccine given?

For both children and adults, the vaccine should be given as three shots. The vaccine is given as follows: a single shot, followed by a second injection one month later, and then a third shot six months later. People who are infected with another virus, such as the human immunodeficiency virus (HIV), or who have problems with their immune system, may need larger doses of the hepatitis B vaccine.

If you are not able to get the shots on time, the vaccine may still work if you get your second and third shots at least two months apart from each other. Ask your doctor for more information.

Babies born to infected mothers should get the first shot within 12 hours after birth, followed by a second shot one month later, and the third shot six months later. Babies born to mothers who are not infected with the hepatitis B virus should get the first shot within one to two months after birth, and the second shot a month later, and the third shot six months later.

You will be protected for about 13 years. If it has been many years since you received your hepatitis B vaccine, or if you do not know when you were vaccinated, ask your doctor to check to see if you have antibodies against hepatitis B.