What are the common and serious adverse effects of the adult hepatitis B vaccine and what corrective action should be taken if a dose is missed or a reaction occurs?

Adverse Effects and Corrective Actions for Adult Hepatitis B Vaccine

Common Adverse Effects

The adult hepatitis B vaccine is extremely safe, with most adverse effects being mild and occurring at rates no higher than placebo. 1

Local reactions:

• Pain at injection site occurs in 3-29% of vaccinees, but placebo-controlled studies show this happens at identical rates in those receiving placebo 1
• Injection site erythema and swelling each occur in approximately 3% of recipients 1
• Injection site induration may occur in <10% of vaccinees 2

Systemic reactions:

• Fever >37.7°C (99.9°F) occurs in 1-6% of vaccinees, again at rates identical to placebo 1
• Headache occurs in 3-14% of recipients 1, 2
• Fatigue occurs in approximately 14% of vaccinees 1, 2
• Nausea, dizziness, and myalgia occur in <10% of recipients 2

These mild reactions require no specific corrective action beyond symptomatic management, and the vaccine series should continue as scheduled. 3

Serious Adverse Effects

The only proven serious adverse event causally linked to hepatitis B vaccine is anaphylaxis, which occurs at a rate of approximately 1 per 1.1 million vaccine doses. 1, 4

Anaphylaxis is an absolute contraindication to further doses:

• If anaphylaxis or severe allergic reaction (generalized urticaria, angioedema, difficulty breathing, wheezing, hypotension, or shock) occurs after any dose, the vaccine series must be discontinued immediately 3
• The patient should not receive any further hepatitis B vaccine doses 3
• Counsel the patient on alternative hepatitis B prevention strategies, including avoiding high-risk exposures and considering hepatitis B immunoglobulin (HBIG) for post-exposure prophylaxis if needed 3

Yeast hypersensitivity:

• Persons with known anaphylactic reaction to yeast (a vaccine component) should not receive hepatitis B vaccine 1, 3, 2

Important clinical context: All vaccines should be administered in settings where personnel are trained to recognize and manage acute hypersensitivity reactions, with epinephrine (1:1,000) and emergency equipment immediately available 3, 2

Conditions NOT Caused by Hepatitis B Vaccine

Multiple high-quality studies have definitively ruled out causal associations between hepatitis B vaccine and the following conditions: 1, 4

• Guillain-Barré syndrome (GBS): Early surveillance suggested a possible association with plasma-derived vaccine, but subsequent analysis of recombinant vaccine showed no increased risk above background rates 1
• Multiple sclerosis: One retrospective study reported an association, but multiple subsequent studies demonstrated no such association 1
• Chronic fatigue syndrome 1
• Diabetes mellitus 1
• Rheumatoid arthritis 1
• Autoimmune diseases 1
• Bell's palsy 1
• Optic neuritis 1

The Institute of Medicine concluded that evidence convincingly supports causation only for anaphylaxis in yeast-sensitive persons, and is inadequate to accept or reject a causal relation between hepatitis B vaccine and neurologic, chronic, and autoimmune diseases. 1, 4

Corrective Action for Missed Doses

If a dose is missed, simply resume the series without restarting—there is no need to repeat previously administered doses. 1

Specific guidance for interrupted schedules:

• If the series is interrupted after the first dose, administer the second dose as soon as possible, then complete the series with appropriate intervals 1
• If only the third dose is delayed, administer it as soon as feasible 1
• Minimum intervals: at least 4 weeks between doses 1 and 2, at least 8 weeks between doses 2 and 3, and at least 16 weeks between doses 1 and 3 1

Management of Non-Responders

For adults who do not achieve protective antibody levels (anti-HBs ≥10 mIU/mL) after the initial 3-dose series:

• Administer one additional dose first, which produces protective antibody levels in 25-50% of initial non-responders 1, 5
• If anti-HBs remains <10 mIU/mL after the single booster, complete a second full 3-dose series, achieving seroprotection in 44-100% of non-responders 1, 5
• ACIP does not recommend more than two vaccine series in non-responders 1

Critical caveat: Immunocompetent adults who previously achieved anti-HBs ≥10 mIU/mL do NOT need routine antibody testing or booster doses, even if titers subsequently fall below 10 mIU/mL, as immunologic memory remains intact for at least 20 years 1, 5

Risk-Benefit Context

Any presumed risk of adverse events must be balanced against the substantial benefit: For each U.S. birth cohort, an estimated 2,000-5,000 persons will die from hepatitis B-related liver disease without vaccination 1, 4