How many doses of hepatitis B (HBV) vaccine are typically administered?

Hepatitis B Vaccine Dosing

The hepatitis B vaccine is administered as a 3-dose series for most populations, with the standard schedule at 0,1, and 6 months, though a 2-dose schedule is available for certain adults using Heplisav-B. 1, 2

Standard 3-Dose Schedules

For the vast majority of patients—infants, children, adolescents, and adults—the hepatitis B vaccine requires 3 doses. 3, 1

Infants and Children

• Infants receive 3 doses on schedules of either 0,1-2, and 6 months or 0,2,4, and 6 months (when using combination vaccines like Pediarix) 3
• The final dose must not be administered before 24 weeks (164 days) of age, regardless of when earlier doses were given 3, 1
• For infants born to HBsAg-positive mothers, the first dose must be given within 12 hours of birth plus HBIG, followed by doses at 1-2 months and 6 months 3, 1

Adolescents (Ages 11-19)

• The standard schedule is 3 doses at 0,1, and 6 months using either Recombivax HB (10 μg) or Engerix-B (10 μg) 3, 2
• An alternative 2-dose schedule exists only for adolescents aged 11-15 years using the adult formulation of Recombivax HB (10 μg) at 0 and 4-6 months 3, 2

Adults (Age ≥18 Years)

• Traditional vaccines (Recombivax HB, Engerix-B, PreHevbrio) require 3 doses at 0,1, and 6 months 1, 2
• Heplisav-B is the only 2-dose vaccine for adults ≥18 years, administered at 0 and 1 month 1, 2

Alternative Schedules

Alternative 3-dose schedules at 0,2, and 4 months or 0,1, and 4 months produce similar seroprotection rates to the standard 0,1, and 6-month schedule. 3, 1

• Longer intervals between the last 2 doses (4-12 months) result in higher final antibody titers 3
• Increasing the interval between the first and second doses has little effect on final immunogenicity 3

Special Populations Requiring Modified Schedules

Hemodialysis Patients and Immunocompromised Adults

• These patients require 3 doses of high-dose (40 μg) Recombivax HB at 0,1, and 6 months 3, 1, 2
• Alternatively, 4 doses of high-dose (40 μg) Engerix-B at 0,1,2, and 6 months 3, 2
• Standard doses are inadequate for this population 1, 2

Accelerated Schedules for Rapid Protection

• Twinrix (combined hepatitis A and B vaccine) can be given on an accelerated 4-dose schedule at 0,7, and 21-30 days, followed by a booster at 12 months 3, 1
• Engerix-B can be administered as 4 doses at 0,1,2, and 12 months 3

Critical Minimum Intervals

The minimum interval between doses 1 and 2 is 4 weeks, between doses 2 and 3 is 8 weeks, and between doses 1 and 3 is 16 weeks. 1, 2

• Doses given ≤4 days before the minimum interval are considered valid 1, 2
• The third dose acts primarily as a booster and provides optimal long-term protection 3

Interrupted Schedules

If the vaccination series is interrupted, do not restart the series—simply continue where you left off. 1, 2

• If interrupted after dose 1, give dose 2 as soon as possible, then dose 3 at least 8 weeks after dose 2 1
• The second and third doses should be separated by ≥8 weeks 2
• Restarting the series wastes doses and delays protection 1, 2

Immunogenicity by Number of Doses

After dose 1,30-55% of individuals achieve protective antibody levels; after dose 2,75% achieve protection; and after dose 3, >90% achieve protection with traditional vaccines 1

• Seroprotection rates exceed 95% in adolescents and young adults after completing the 3-dose series 3
• Heplisav-B achieves approximately 90% seroprotection compared to 70.5-90.2% with Engerix-B 1

Common Pitfalls to Avoid

• Never restart the series if interrupted, as this wastes doses and delays protection 1, 2
• Do not give the third dose before 16 weeks from the first dose, even if 8 weeks have passed since the second dose 1, 2
• Do not give the final infant dose before 24 weeks of age, as this may compromise long-term immunity 3, 1
• Do not use standard adult doses in hemodialysis patients—they require 40 μg doses 1, 2
• Do not use Heplisav-B or PreHevbrio in pregnant women, children, or hemodialysis patients 1, 2