The hepatitis B vaccine is a series of three injections, according to the Hepatitis B Foundation. There is also a two-dose hepatitis B vaccine for adolescents.
People may receive the first injection in the series at any time, according to the Hepatitis B Foundation. The second injection follows within one month of the initial injection, with the third and final dose given six months after the first dose. Doctors recommend the vaccine for health care personnel, sexually active adults and teens, homosexual men, diabetics and patients with kidney disease, among others. Doctors also recommend the vaccine for people traveling to countries where hepatitis B is prevalent.