Hepatitis B vaccine is to prevent the occurrence of Hepatitis B virus being transmitted or proliferate within the infants body. The vaccine is available as a monovalent vaccine as well as a combination vaccine with other vaccines related to illnesses such as Diphtheria, Tetanus and Pertusis.
The vaccine is designated to be initiated at birth and therefore the first dose is scheduled to be given before the mother and the child is discharged from the hospital. The vaccine used for this purpose will be the monovalent Hepatitis B vaccine and it should be remembered that the combination or other types of hepatitis B vaccine should not be used in infants less than 6 weeks of age.
When the mother of the newborn is found to be positive for Hepatitis B surface antigen, the infant should receive the hepatitis B vaccine as well as 0.5 ml of hepatitis B immunoglobulin before 12 hours from the time of delivery.
In case the mother’s Hepatitis B status is not known, the mother should be checked for her status immediately and the infant should only be given the hepatitis B vaccine before discharge. But, once the hepatitis B surface antigen status is known and is positive, the infant should be given the immunoglobulin injection within 1 week after birth.
2nd and the 3rd dose:
Following the vaccination at birth, the infant should be given two more doses of hepatitis B vaccine which can be either in the monovalent form or else in the combination form. If the monovalent form is used, the 4th dose of the same vaccine is not so indicated, but, in case of combined vaccines, it would warrant the use of a 4th dose no earlier than 24 weeks.
The provision is given by the guidelines to give the 2nd dose of the hepatitis B vaccine at 1 – 2 months following birth and this will be followed by a 3rd dose between 6 to 18 months but not earlier than 24 weeks. It should also be remembered that, the gap between the two vaccine doses should at least be 4 weeks from the last dose.
Once the vaccinations are complete, in case the infant has a risk of developing Hepatitis B at birth, the surface antigens for Hepatitis B should be checked along with the antibodies against the hepatitis B surface antigen.
Thus, the things to remember in vaccinating for hepatitis B in infants are the 3 doses given at birth, at 1 – 2 months and between 6 – 18 months. At the same time, not using the combination vaccine before the age of 6 weeks and not giving the last dose before 24 weeks are also equally important.