Infants born to mothers who are hepatitis B surface antigen–positive are recommended to receive both hepatitis B vaccine and HBIG
All newborns of mothers known to have chronic hepatitis B must receive both:
- a birth dose of monovalent hepatitis B vaccine and
- hepatitis B immunoglobulin (HBIG)
These should both be given on the day of birth, at the same time but in separate thighs.
The dose of HBIG is 100 IU given by intramuscular injection. Infants should receive HBIG immediately after birth — preferably within 12 hours of birth and certainly within 48 hours. Its efficacy decreases markedly if given more than 48 hours after birth.
Give the dose of monovalent hepatitis B vaccine preferably within 24 hours of birth, and definitely within 7 days. This regimen results in seroconversion rates of more than 90% in neonates, even with concurrent administration of HBIG.
Do not delay vaccination beyond 7 days after birth, because vaccination alone is reasonably effective in preventing infection if it is given early enough.21 Infants should receive 3 subsequent doses of a hepatitis B–containing vaccine at 2, 4 and 6 months of age, so that they receive a total of 4 doses of hepatitis B–containing vaccines.
Measuring antibody and HBsAg levels after vaccine and immunoglobulin administration
Measure levels of hepatitis B surface antigen (HBsAg) and anti-HBs (antibody to HBsAg) in infants born to mothers with chronic hepatitis B 3–12 months after completing the primary vaccine course.
Do not test the infant before 9 months of age, to avoid detecting anti-HBs from the HBIG given at birth.
The infant is protected against hepatitis B if:22
- anti-HBs levels are adequate (≥10 mIU per mL) and
- HBsAg is negative
If the anti-HBs level is <10 mIU per mL, seek expert advice about revaccination or further testing.
Screening also enables appropriate:
- hepatitis B immunoglobulin
- international units
- hepatitis B surface antigen
- antibody to hepatitis B surface antigen