HEPATITIS B VACCINE

HEPATITIS B VACCINE

Hepatitis B vaccine consists of hepatitis surface antigen related protein- a highly purified suspension of inactivated, alum-adsorbed HBsAG particles. Now only DNA recombitant, i.e. genetically engineered (Engerix-B, Shanvac-B,HB Vac, Enivac HB, Revac-B) vaccine is in vogue worldwide. The world health Organization (WHO) recommends incorporation of the hepatitis B vaccine as the seventh vaccine in the routine immunization schedule in the south-East Asia and the Pacific.

Indications

IAP now recommends it as a routine vaccine. High risk situation in which it must be given include

1. recipients of multiple blood transfusions
2. household sexual contacts of carriers of HBV
3. users of Parenteral drugs such as heroin
4. hemosexually active males
5. hemodialysis subjects
6. immigrants from areas of high HBV endemicity
7. babies born to mothers with HBsAG positive blood

Dose

The vaccine is administered intramuscularly in a dose of 0.5 ml(10 mcg) and 1ml(20mcg) for children below and above 10 years, respectively. IAP recommends it at birth, 6 weeks and 14 weeks or 6,10 and 14 weeks. Else, it may be given in two doses 1 month apart followed by a booster 6 months later.

Postexposure prophylaxis According to IAP recommendation, if the pregnant woman is known carrier of HB virus, her neonate should be given HB immune globulin (HBlg) within 12 hours of birth and also one dose of HB vaccine with a separate syringe and needle over a different site on the body. If HBlg is not available, HB vaccine must be given. If there has been a delay of over 12 hours, HBlg need not be given, However, HB vaccine has got to be started. The second dose of the vaccine is given 4 weeks later and the third 5 weeks (4-6 weeks) later. It may well be convenient to give the third dose at the same time as measles vaccine, at or after 9 months.

In case the mother is known not to be a carrier of HB, there is no need to give HB vaccine immediately after birth. It can conveniently be given at the first visit  for other vaccines, such as 6 weeks when a dose of DTP is due. The second dose of HB vaccine may be given 4 weeks later and the third at the time of measles vaccine.

Contraindications

Hypersensitivity to its components.

Adverse Reactions

1. Transient soreness, erythema and induration at injection site.
2. Low grade fever

There is no evidence that it causes development or flare-up of demyelinating diseases such as multiple sclerosis (suspected in France a few years ago).

Storage

2-8 degree C