Hepatitis B vaccine is given to babies after the first month of life. There are three shots of Hepatitis B vaccine, the first one is given within two hours after birth and no later than 24 hours after birth, then the second one is given one month later and the third one is given when the baby is 6 months old. The hepatitis B vaccine is a national class I vaccine and is free for newborns. The main purpose of giving your child the hepatitis B vaccine is to make your child’s body produce strong antibodies to resist the infection of the hepatitis B virus and thus reduce the probability of getting hepatitis B. The hepatitis B vaccine is the most effective measure to prevent the hepatitis B virus.