Hepatitis B Vaccination Schedule for Children
The first dose of hepatitis B vaccine should be administered at birth (within 24 hours), with subsequent doses at 1-2 months and 6 months of age. This is not a question about which "month" the government provides vaccinations, but rather the age-based schedule when children receive their hepatitis B vaccine series.
Standard Vaccination Schedule
The hepatitis B vaccine series follows a three-dose schedule 1:
- First dose (Dose 1): Birth (within 24 hours of delivery) 1, 2
- Second dose (Dose 2): 1-2 months of age 1
- Third dose (Dose 3): 6 months of age (but not before 24 weeks/164 days of age) 1, 3
The birth dose is critical as a safety net to prevent perinatal transmission, particularly since some mothers may have unrecognized hepatitis B infection 1, 4. All medically stable infants weighing ≥2,000 grams should receive the first dose before hospital discharge 1, 5.
Timing Requirements and Intervals
The minimum intervals between doses must be respected 3:
- Dose 1 to Dose 2: Minimum 4 weeks 1, 3
- Dose 2 to Dose 3: Minimum 8 weeks 1, 3
- Dose 1 to Dose 3: Minimum 16 weeks 3
- Final dose: Must not be given before 24 weeks (164 days) of age, regardless of earlier dose timing 1, 3
Special Populations Requiring Modified Schedules
Infants Born to HBsAg-Positive Mothers
These high-risk infants require immediate intervention 1:
- First dose + HBIG: Within 12 hours of birth at separate anatomical sites 1, 3
- Second dose: 1-2 months of age 1
- Third dose: 6 months of age 1
- Post-vaccination testing: At 9-15 months for HBsAg and anti-HBs 3
Delaying the birth dose beyond 12 hours significantly increases infection risk in these infants 3.
Low Birth Weight Infants (<2,000 grams)
For infants born to HBsAg-negative mothers and weighing <2,000 grams, the first dose should be delayed until hospital discharge or 1 month of age 1. However, infants <2,000 grams born to HBsAg-positive mothers still require the birth dose plus HBIG within 12 hours 1.
Catch-Up Vaccination for Older Children
All children and adolescents aged <19 years who have not been vaccinated should receive the hepatitis B vaccine series at any age 1, 4. The standard 0,1,6-month schedule applies 1. If the series is interrupted, do not restart—simply continue from where you left off 3.
Expected Immune Response
Approximately 95-100% of healthy children achieve protective antibody levels (≥10 mIU/mL) after completing the 3-dose series 6, 7. The protective efficacy against perinatal transmission is 90-100% when the birth dose is administered with HBIG to infants of HBsAg-positive mothers 7.
Critical Pitfalls to Avoid
- Never delay the birth dose in medically stable infants ≥2,000 grams born to HBsAg-negative mothers—it should be given within 24 hours 1, 5
- Never give the final dose before 24 weeks of age, as this may compromise long-term immunity 1, 3
- Never restart an interrupted series—simply continue where you left off 3
- Do not perform routine post-vaccination testing in healthy children, even those who are household contacts of HBsAg-positive individuals 6
Duration of Protection
Vaccine-induced immunity persists for at least 10-30 years in immunocompetent individuals who achieve adequate initial antibody response 6, 3. Booster doses are not routinely recommended for immunocompetent children who complete the primary series 6.