The hepatitis B vaccine series typically consists of three injections. The patient may receive the first injection at any time. He must receive the second injection at least one month after the first and the third at least six months after the first dose, according to the Hepatitis B Foundation.
The Centers for Disease Control and Prevention recommends the hepatitis B vaccine for all infants, with administration of the first dose at birth. The CDC also recommends the vaccine for all individuals under age 19 who have not received it. Unvaccinated adults should receive the hepatitis B vaccine if they have a sex partner with hepatitis B, have more than one sex partner, are exposed to blood and body fluids while working, have HIV, or share needles, syringes or other equipment for injecting drugs. People with chronic kidney or liver disease and those who have frequent close contact with a person infected with hepatitis B should also receive the vaccine.
People with a history of allergic reaction to yeast or any vaccine ingredients should not receive the hepatitis B vaccine, explains the CDC. The most common side effect of the vaccine is discomfort at the injection site. As of 2015, more than 100 million people have received the hepatitis B vaccine, and none have reported serious side effects.