3.1 Hepatitis B vaccine (HepB)
3.1.1 What is HepB vaccine?
Hepatitis B diseases are discussed in Study Session 4 of the Communicable Diseases Module, Part 1.
Hepatitis B (HepB) vaccine protects against the hepatitis B diseases, which affect the liver and are caused by hepatitis B viruses. If a child is infected with hepatitis B viruses, liver disease may develop many years later in adult life. In Ethiopia, HepB vaccine is routinely given to infants as one of the five vaccines combined in the pentavalent vaccine (which also protects against diphtheria, pertussis, tetanus and Haemophilus influenzae type b). The four antibacterial vaccines in the pentavalent vaccine used in Ethiopia were described in Study Session 2.
HepB vaccine is a recombinant vaccine. What does this mean?
A recombinant vaccine is produced by inserting genetic material from a disease-causing infectious agent into harmless cells in the laboratory. The cells with the new genes begin to manufacture the unique antigens that identify the infectious agent. These antigens are then purified and used in the vaccine.
HepB vaccine is also available on its own as a single vaccine, which may be given to healthworkers as a ‘booster’ to increase their protection against infection by bloodborne hepatitis B viruses from patients. The vaccination schedule in adults is not the same as the schedule you already know for infants, who receive HepB vaccine as part of the pentavalent vaccine in the Ethiopian EPI.
How many doses and at what ages should infants receive pentavalent vaccine containing HepB vaccine? What is the route of administration?
They should receive three doses of pentavalent vaccine at the age of 6, 10 and 14 weeks, as you learned in Study Session 2. The route of administration is by intramuscular injection into the left outer upper thigh muscle.
The HepB component of the pentavalent vaccine is very safe and effective: up to 95% of infants who receive all three doses of pentavalent vaccine are protected against hepatitis B virus infection. The contraindications are the same as already described for pentavalent vaccine: infants with a high-grade fever should not be vaccinated until they recover. An infant who develops a severe allergic reaction, swollen lymph glands or encephalopathy to a previous dose of pentavalent vaccine should not be given another dose.
Do you remember the storage conditions for pentavalent vaccine containing HepB vaccine and the four antibacterial vaccines?
The vaccine vials should be stored in a refrigerator at between +2oC and +8oC, and never frozen.
Learning Outcomes for Study Session 3