Vaccine Pregnancy: The effect of HBsAg on foetal development has not been assessed; however, as with all inactivated viral vaccines, harm to the foetus is not expected. Engerix B should be used during pregnancy only when clearly needed and when the possible advantages outweigh the possible risks for the foetus. Breast-feeding: the effect on breastfed infants of administration to their mothers has not been evaluated and excretion into breast milk is not known, but no contraindication has been established. Fertility: not evaluated in fertility studies.

Hepatitis B vaccine

Brand names: Engerix B, HBvaxPro, Fendrix

Hepatitis B vaccine is a recombinant vaccine used for active immunisation against hepatitis B virus, given as part of the routine childhood schedule and to adults at increased occupational or clinical risk.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 20 micrograms in 1.0 ml per dose, for subjects 16 years of age and above

Route: Intramuscular injection into the deltoid region in adults and children (anterolateral thigh in neonates, infants and young children). Exceptionally the vaccine may be given subcutaneously in patients with thrombocytopenia or bleeding disorders. It should not be given in the buttock or intradermally (lower immune response) and under no circumstances intravascularly

Frequency: Primary immunisation, subjects 16 years and above — either a 0, 1, 6 months schedule (optimal protection at month 7, high antibody concentrations) or an accelerated 0, 1 and 2 months schedule, in which case a fourth dose should be given at 12 months to assure long-term protection

Source product is the correct adult monovalent presentation: Engerix B 20 micrograms/1 ml suspension for injection in pre-filled syringe (adult) — the previous bundle for this id was Ambirix, a combined hepatitis A + B paediatric/adolescent vaccine, and has been replaced. RAPID SCHEDULE (18 years and above): in exceptional circumstances where even more rapid induction of protection is required (e.g. travellers starting the course within one month of departure to areas of high endemicity), three intramuscular injections at 0, 7 and 21 days may be used, with a fourth dose recommended 12 months after the first dose. KNOWN OR PRESUMED EXPOSURE TO HBV (e.g. needlestick with a contaminated needle): the first dose can be given simultaneously with hepatitis B immune globulin (HBIg), which must be given at a separate injection site; the 0, 1, 2-12 months schedule should be advised. BOOSTERS: current data do not support the need for boosters in immunocompetent subjects who responded to a full primary course; in immunocompromised subjects (e.g. chronic renal failure, haemodialysis, HIV positive) boosters should be given to maintain anti-HBs at or above 10 mIU/ml, with post-vaccination testing every 6-12 months. Schedules may be adjusted to accommodate local immunisation practice; national recommendations on boosters should be considered. PAEDIATRIC (not weight-based, so no structured paediatric dose is given): the 10 microgram/0.5 ml presentation is intended for subjects up to and including 15 years of age, including neonates, using either 0, 1, 6 months or the accelerated 0, 1, 2 months plus 12 months schedule; neonates born of HBV-carrier mothers should start at birth with the 10 microgram vaccine (0, 1, 2 and 12 months gives a more rapid response than 0, 1 and 6 months), with HBIg given simultaneously at a separate site when available. The 20 microgram vaccine may also be used from 11 up to and including 15 years as a 2-dose 0, 6 months schedule, but only where the risk of hepatitis B infection during the course is low and completion of the two doses can be assured — otherwise use the three-dose or accelerated schedule of the 10 microgram/0.5 ml vaccine. Verify paediatric doses and schedules against the 10 microgram product SPC and current national immunisation guidance. Preterm infants born at or before 28 weeks of gestation: consider the potential risk of apnoea and the need for respiratory monitoring for 48-72 hours after the primary series.

Dose adjustments

Renal

Renal insufficiency including haemodialysis, 16 years of age and above: the primary immunisation schedule is four DOUBLE doses (2 x 20 micrograms) at elected date, 1 month, 2 months and 6 months from the date of the first dose; the schedule should be adapted to ensure anti-HBs antibody concentrations remain at or above the accepted protective level of 10 IU/l. Up to and including 15 years of age: either the 0, 1, 2 and 12 months or the 0, 1, 6 months schedule of the 10 microgram vaccine can be used; based on adult experience a higher antigen dosage may improve the immune response. Consideration should be given to serological testing after vaccination, and additional doses may be needed to ensure a protective anti-HBs level of 10 mIU/ml or more.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Known hypersensitivity to the active substances or to any of the excipients listed in section 6.1
Subjects having shown signs of hypersensitivity after previous Engerix B administration
Administration should be postponed in subjects suffering from acute severe febrile illness (a minor infection is not a contraindication)

Side effects

Pain and redness at the injection site, fatigue, and irritability — very common (>=1/10); headache — very common in paediatric use
Fever (>=37.5 degrees C), malaise, swelling at the injection site and injection site reaction such as induration — common; headache and drowsiness in adults — common
Loss of appetite — common; gastrointestinal symptoms such as nausea, vomiting, diarrhoea and abdominal pain — common
Dizziness, myalgia and influenza-like illness — uncommon; lymphadenopathy, paraesthesia, arthralgia, urticaria, pruritus and rash — rare
Post-marketing (frequency not known): anaphylaxis, allergic reactions including anaphylactoid reactions and reactions mimicking serum sickness, polyarteritis nodosa, thrombocytopenia, meningitis, encephalitis, encephalopathy, convulsions, paralysis, neuritis (including Guillain-Barre syndrome, optic neuritis and multiple sclerosis), neuropathy, hypoaesthesia, vasculitis and hypotension. Syncope can also occur before or after vaccination, especially in adolescents (section 4.4)

Clinical monograph

How it works

It contains recombinant hepatitis B surface antigen which stimulates production of protective anti-HBs antibodies and immunological memory against the virus.

Prescribing in practice

It is contraindicated in those with a confirmed anaphylactic reaction to a previous dose or a vaccine component, and the full course is required for reliable protection.
Some at-risk and immunocompromised individuals need post-vaccination antibody testing and may require reinforcing or higher-antigen schedules.
Administer intramuscularly and follow the relevant Green Book chapter, the SPC and current prescribing references for schedules and combination vaccines.

Monitoring

Post-vaccination anti-HBs testing is recommended for selected groups such as healthcare workers and renal patients to confirm an adequate response.

Counselling the patient

Complete every dose in the schedule, as partial courses may not give protection.
Some people, such as healthcare workers, need a blood test afterwards to check the response.
Injection-site soreness and mild tiredness are common and usually short-lived.

Evidence & guidelines

Hepatitis B vaccination schedules and the use of post-vaccination antibody testing for at-risk groups are set out in the UK immunisation guidance (the Green Book).

Reference: UK Green Book; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

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