Hepatitis B Vaccine Spacing
The standard hepatitis B vaccine schedule is 3 doses administered at 0,1, and 6 months for most populations, with minimum intervals of 4 weeks between doses 1 and 2,8 weeks between doses 2 and 3, and 16 weeks between doses 1 and 3. 1, 2
Standard Schedules by Population
Infants
- First dose within 12 hours of birth (before hospital discharge), second dose at 1-2 months, and third dose at 6 months 1, 2
- For infants born to HBsAg-positive mothers: first dose within 12 hours of birth plus HBIG, then at 1-2 months and 6 months 1, 2
- The final dose must not be administered before 24 weeks of age, regardless of when earlier doses were given 2
- Schedules with 2-month intervals between doses produce good antibody response and may be appropriate when ensuring follow-up is difficult 3
- Highest antibody titers are achieved when the last two doses are spaced at least 4 months apart 3
Adolescents and Adults
- Preferred schedule: 0,1, and 6 months 3, 1, 2, 4
- Alternative schedules (0,2, and 4 months or 0,1, and 4 months) produce similar seroprotection rates and may be used to achieve complete vaccination when adherence is a concern 3
- For adolescents ages 11-15 years: a 2-dose schedule at 0 and 4-6 months using adult formulation of Recombivax HB is an option 4
Special Populations
- Hemodialysis patients and immunocompromised adults: 40 μg doses at 0,1, and 6 months (not standard adult doses) 1, 2, 4
- Annual anti-HBs testing recommended with booster doses when levels fall below 10 mIU/mL 1, 2
Accelerated Schedules for Rapid Protection
When immediate protection is needed (e.g., travelers departing soon, high-risk exposures):
- Engerix-B: 0,1,2, and 12 months (4-dose schedule) 2, 4
- Twinrix (combined hepatitis A and B): 0,7, and 21-30 days, followed by a dose at 12 months 1, 2
- These accelerated schedules provide faster seroconversion but require the fourth dose at 12 months for long-term protection 5
Critical Minimum Intervals
Never violate these minimum intervals (doses given ≤4 days before minimum are considered valid): 1, 2, 4
- Between doses 1 and 2: 4 weeks minimum
- Between doses 2 and 3: 8 weeks minimum
- Between doses 1 and 3: 16 weeks minimum
Interrupted Schedules
If the vaccination series is interrupted, do NOT restart the series—simply continue where you left off. 2, 4 This is a common pitfall that wastes doses and delays protection. 2
- If interrupted after dose 1: give dose 2 as soon as possible, then dose 3 at least 8 weeks after dose 2 2
- Increasing the interval between doses has little effect on final immunogenicity 3
- Longer intervals between the last 2 doses result in higher final antibody levels 3
Immunogenicity by Schedule
The standard 0,1,6-month schedule produces: 3
- 30-55% protective antibody response after dose 1
- 75% after dose 2
90% after dose 3 in adults <40 years
After age 40, response rates decline below 90%, and by age 60, only 75% achieve protective levels. 3
Common Pitfalls to Avoid
- Never restart the series if interrupted—this wastes doses and delays protection 2, 4
- Do not give the third dose before 16 weeks from the first dose, even if 8 weeks have passed since the second dose 2
- Do not give the final infant dose before 24 weeks of age—this may compromise long-term immunity 2
- Do not use standard adult doses in hemodialysis patients—they require 40 μg doses 1, 2
- Delaying the birth dose beyond 12 hours for infants born to HBsAg-positive mothers significantly increases infection risk 1
Post-Vaccination Testing
Testing is recommended 1-2 months after completing the series for: 1, 2
- Infants born to HBsAg-positive mothers
- Healthcare personnel
- Hemodialysis patients
- HIV-infected persons
- Other immunocompromised persons
An anti-HBs level ≥10 mIU/mL indicates adequate protection. 1, 2